Chip embedded power converters

ABSTRACT

A direct current to direct current (DC-DC) converter can include a chip embedded integrated circuit (IC), one or more switches, and an inductor. The IC can be embedded in a PCB. The IC can include driver, switches, and PWM controller. The IC and/or switches can include eGaN. The inductor can be stacked above the IC and/or switches, reducing an overall footprint. One or more capacitors can also be stacked above the IC and/or switches. Vias can couple the inductor and/or capacitors to the IC (e.g., to the switches). The DC-DC converter can offer better transient performance, have lower ripples, or use fewer capacitors. Parasitic effects that prevent efficient, higher switching speeds are reduced. The inductor size and overall footprint can be reduced. Multiple inductor arrangements can improve performance. Various feedback systems can be used, such as a ripple generator in a constant on or off time modulation circuit.

CROSS REFERENCE TO RELATED APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 C.F.R. § 1.57in their entirety for all purposes. This application is a continuationof U.S. application Ser. No. 16/258,254, filed on Jan. 25, 2019, andtitled “CHIP EMBEDDED POWER CONVERTERS”, which is a continuation of U.S.application Ser. No. 15/669,838 filed on Aug. 4, 2017, and titled “CHIPEMBEDDED POWER CONVERTERS”, which is a continuation-in-part of U.S.patent application Ser. No. 15/428,019, filed on Feb. 8, 2017 (issued onAug. 8, 2017 as U.S. Pat. No. 9,729,059), and titled “CHIP EMBEDDEDDC-DC CONVERTER,” which claims the benefit of U.S. Provisional PatentApplication No. 62/293,241, filed Feb. 9, 2016. The entireties of theseapplications are hereby incorporated by reference for all purposes.

BACKGROUND Field

This disclosure relates to electronic systems, direct current to directcurrent (DC-DC) converters, electronic device design, and electronicdevice production technology.

Description of the Related Art

Although various DC-DC converters are known, these DC-DC converters aremade of non-ideal components and/or arrangements that suffer fromparasitic losses and inefficiencies. There exists a need for improvedpower converters.

SUMMARY

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter, comprising: a lower printed circuit board (PCB)part having a bottom side and a top side; an upper printed circuit board(PCB) part having a bottom side and a top side; embedded circuitry thatis between the top side of the lower PCB part and the bottom side of theupper PCB part, the embedded circuitry comprising: a pulse widthmodulator; and at least one switch; one or more vias extending throughthe upper PCB part; an inductor positioned over the top side of theupper PCB part, wherein the one or more vias are electrically coupled tothe inductor and to the embedded circuitry. The embodiments can featureany combination of: wherein the embedded circuitry includes anintegrated circuit (IC); wherein a footprint of the inductor at leastpartially overlaps a footprint of the integrated circuit; wherein nowire-bonds electrically interconnect the inductor and the embeddedcircuitry; wherein the circuitry has a switching rate of at least 1 MHz;wherein the circuitry has a switching rate of at least 3 MHz; whereinthe circuitry has a switching rate of at least 5 MHz; wherein thecircuitry has a switching rate of up to 7 MHz; wherein the at least oneswitch comprises an enhanced gallium nitride field effect transistor(eGaN FET); further comprising one or more capacitors disposed over thetop side of the upper PCB part; further comprising a core disposedbetween the top side of the lower PCB part and the bottom side of theupper PCB part, wherein the core has one or more pockets formed therein,and wherein the embedded circuitry is disposed in the one or morepockets; wherein the DC-DC power converter has a footprint that issmaller than 25 mm²; wherein the DC-DC power converter has a footprintthat is smaller than 10 mm²; wherein the DC-DC power converter has afootprint that is smaller than 5 mm²; wherein the DC-DC power converterhas a footprint that is as small as 2 mm²; wherein the DC-DC powerconverter has a footprint area that is between 0.5 and 10 mm² peramperage of current.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter package comprising: an integrated circuit (IC)chip embedded in at least one printed circuit board (PCB), the IC chipcomprising a driver; an inductor positioned outside of the chip embeddedpackage and coupled to a surface of the chip embedded package; and a viaelectrically coupling the inductor to the IC chip; wherein a footprintof the inductor overlaps, at least partially, with a footprint of the ICchip. The embodiments can feature any of: wherein a transistor isembedded in the at least one PCB, and wherein the inductor iselectrically coupled to the transistor; wherein the IC chip comprises: apulse width modulator (PWM) controller coupled to the driver, and aswitching transistor coupled to an output of the driver; furthercomprising a switch comprising enhanced gallium nitride (eGaN); whereinthe switch is configured to switch at 4 MHz or faster; wherein theswitch is configured to switch at 5 MHz or faster; further comprising aswitch comprising at least one of silicon or gallium arsenide.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter in a single package comprising: an enhancedgallium nitride (eGaN) component embedded, at least partially, inside ofa mounting substrate; an inductor mounted outside of the mountingsubstrate; and a via coupling the inductor to the eGaN component;wherein a footprint of the inductor overlaps, at least partially, with afootprint of the eGaN component. The embodiments can feature anycombination of: wherein the mounting substrate is a multi-layer PCB;wherein the eGaN component is a switch comprising eGaN, the DC-DC powerconverter further comprising a driver circuit configured to drive theswitch; wherein the driver and the switch are part of an IC chip;wherein the IC chip further comprises a pulse width modulator (PWM)controller.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter utilizing a chip embedded package, the DC-DCconverter comprising: an enhanced gallium nitride (eGaN) switch insideof a printed circuit board (PCB); a pulse width modulator (PWM)controller; a driver embedded inside of the PCB, wherein the PWMcontroller and the driver are configured to drive the eGaN switch at afrequency of 1 MHz or higher; an inductor positioned outside of the chipembedded package and coupled to a surface of the PCB; and a viaelectrically coupling the inductor to the eGaN switch. The embodimentscan feature wherein the driver is configured to drive the eGaN switch ata frequency of 5 MHz or higher.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: a printed circuit board; and anintegrated circuit inside of the printed circuit board, the integratedcircuit comprising a driver. The embodiments can feature any combinationof: further comprising an inductor electrically coupled to theintegrated circuit by one or more vias that extend through the printedcircuit board; wherein the inductor has a footprint that at leastpartially overlaps a footprint of the integrated circuit.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: an integrated circuit comprising adriver; and an inductor vertically stacked above the integrated circuitsuch that a footprint of the inductor overlaps, at least partially, witha footprint of the integrated circuit, wherein the inductor iselectrically coupled to the integrated circuit. The embodiments canfeature any combination of: further comprising a printed circuit board(PCB) having a first side and a second side that is opposite the firstside, wherein the integrated circuit is mounted on the first side of thePCB, and wherein the inductor is mounted on the second side of the PCB;wherein the inductor is electrically coupled to the integrated circuitby one or more vias that extend through the printed circuit board.

Some embodiments are disclosed for a direct current to direct current(DC-DC) buck converter comprising: one or more switches; a driverconfigured to drive the one or more switches; and an inductorelectrically coupled to the switches; wherein the footprint of the DC-DCbuck converter is less than 65 mm²; wherein the DC-DC buck converter isconfigured to receive at least 20 amps of current; and wherein the DC-DCbuck converter is configured to output at least 20 amps of current.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: one or more switches; a driverconfigured to drive the one or more switches at a frequency, thefrequency being between 1 and 5 MHz inclusive; and an inductorelectrically coupled to the one or more switches; wherein the footprintof the DC-DC converter is less than or equal to 10 mm²; wherein theDC-DC converter is configured to receive at least 5 amps of current;wherein the DC-DC converter is configured to output at least 5 amps ofcurrent.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: a first switch coupled to a firstinductor; a second switch coupled to a second inductor; and anintegrated circuit chip embedded in a printed circuit board; wherein thefirst switch and the second switch are coupled to a modulator; andwherein the first inductor and the second inductor are coupled to avoltage output node. The embodiments can feature any combination of:wherein the modulator is included in the integrated circuit chip;wherein the modulator is configured to cause the first switch and thesecond switch to operate output of phase with a synchronous period;wherein an output signal at the output node is a superposition of afirst signal through the first inductor and a second signal through thesecond inductor.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: an integrated circuit chip embeddedin a printed circuit board, the integrated circuit chip comprising adriver; a first switch coupled to the driver; an inductor coupled to thefirst switch; and a feedback path from an output node to a modulatorcircuit. The embodiments can feature any combination of: wherein themodulator circuit is a voltage mode modulator circuit: wherein themodulator circuit is a constant on time or constant off time modulatorcircuit: wherein the modulator circuit is included in the integratedcircuit chip: wherein the modulator circuit and the inductor areincluded in a package with the integrated circuit chip.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter comprising: an integrated circuit chip embeddedin a printed circuit board, the integrated circuit chip comprising adriver; a first switch coupled to the driver; an inductor coupled to thefirst switch; a feedback path from an output node to a modulatorcircuit; and a ramp generator. The embodiments can feature anycombination of: wherein the feedback path and an output from the rampgenerator are coupled to a comparator; further comprising a referencevoltage source coupled to the comparator; wherein the ramp generator isconfigured to emulate a ripple current through the inductor; wherein theramp generator comprises; a first current source, a second currentsource, and a capacitor; wherein the first current source and the secondcurrent source are configured to be trimmed based, at least in part, onan inductance of the inductor; wherein the ramp generator and theinductor are included in the same DC-DC power converter package; whereinthe ramp generator is configured to generate an output signal that isunaffected by an output capacitor coupled to the inductor; wherein theramp generator is configured to generate an output signal that isindependent from the equivalent series resistance (ESR) of an outputcapacitor coupled to the inductor; further comprising an outputcapacitor having a sufficiently low ESR such that a ripple voltageacross the output capacitor is too small to reliably provide to amodulation circuit.

Some embodiments are disclosed for a ramp generator comprising: a firstcurrent source coupled to a supply voltage; a second current sourcecoupled to ground; and a capacitor coupled between the first currentsource and the second current source. The embodiments can feature anycombination of: wherein the ramp generator is configured to emulate aripple current through an inductor in a DC-DC converter; wherein theoutput of the first current source is based, at least in part, on aninput voltage to a DC-DC converter; wherein the output of the firstcurrent source is based, at least in part, on an inductance of aninductor in a DC-DC converter; wherein the output of the second currentsource is based, at least in part, on an inductance of an inductor in aDC-DC converter; wherein the output of the second current source isbased, at least in part, on an inductance of an inductor in a DC-DCconverter; wherein the first current source is configured to be trimmedbased, at least in part, on an inductance of an inductor in a DC-DCconverter; wherein the second current source is configured to be trimmedbased, at least in part, on an inductance of an inductor in a DC-DCconverter.

Some embodiments are disclosed for a method for making a chip embeddeddirect current to direct current converter comprising: embedding anintegrated circuit chip in a printed circuit board; coupling a firstinductor to the printed circuit board; and coupling a second inductor tothe printed circuit board, the first inductor and the second inductorboth coupled to an output node.

Some embodiments are disclosed for a method for converting first directcurrent voltage to a second direct current voltage comprising: driving afirst switch coupled to a first inductor; driving a second switchcoupled to a second inductor, wherein the first switch and the secondswitch are coupled to an output node; and modulating the driving of thefirst switch and the second switch out of phase; wherein at least one ofa driver or a modulator is included in a chip embedded in a printedcircuit board.

Some embodiments are disclosed for a method for making a chip embeddeddirect current to direct current converter comprising: embedding anintegrated circuit chip in a printed circuit board; coupling an inductorbetween the integrated circuit chip and an output node; and providing afeedback path from the output node to a modulator circuit, wherein themodulator circuit includes a ramp generator. The embodiments can featureany combination of: wherein the modulator circuit is included in theprinted circuit board; wherein the modulator circuit is a constant ontime or constant off time modulator circuit; wherein the ramp generatoris included in the integrated circuit; further comprising trimming theramp generator based at least in part on the property of the inductor;wherein the ramp generator is the ramp generator of any previousembodiment.

Some embodiments are disclosed for a method for using a direct currentto direct current converter comprising: receiving input power at aninput node; providing power through a switch to an inductor; storingenergy in an output capacitor such that an output voltage forms acrossthe output capacitor; providing output power at the output voltage to anoutput node; providing the output voltage to a modulator circuit;generating a ripple voltage that is independent of an output capacitor;providing the ripple voltage to the modulator circuit; modulating theswitch based at least in part on an output of the modulator circuit. Theembodiments can feature any combination of: further comprising comparingat least two of: the ripple voltage, a reference voltage, and the outputvoltage; further comprising trimming a current source based at least inpart on an inductance of the inductor; wherein the ripple voltage isgenerated by a ramp generator configured to emulate a current throughthe inductor.

Some embodiments are disclosed for a direct current to direct current(DC-DC) power converter package comprising: an integrated circuit (IC)chip embedded in at least one printed circuit board (PCB), the IC chipcomprising a driver; an inductor positioned outside of the chip embeddedpackage and coupled to a surface of the chip embedded package; and anovercurrent protection circuit configured to detect when a currentprovided to the inductor exceeds a limit. The embodiments can featureany combination of: the overcurrent protection circuit comprises acurrent source configured to be adjusted or trimmed based at least inpart on an Inter-Integrated Circuit or Power Management Bus command; asaturation inductance of the inductor exceeds the limit and exceeds thelimit by less than 50%; the limit exceeds a maximum specified DC currentspecification plus maximum alternating current ripple specification byless than 50%.

Some embodiments disclosed herein can relate to a direct current todirect current (DC-DC) power converter package comprising: an integratedcircuit (IC) chip embedded in at least one printed circuit board (PCB),the IC chip comprising a driver; an inductor positioned outside of thechip embedded package and coupled to a surface of the chip embeddedpackage; and an Inter-Integrated Circuit or Power Management Bus. Theembodiments can have any combination of: wherein the Inter-IntegratedCircuit or Power Management Bus is coupled to at least one currentsource and configured to provide a protocol command to adjust or trimthe current source; wherein the Inter-Integrated Circuit or PowerManagement Bus is coupled to at least one current source and configuredto provide a protocol command to set or adjust a reference valueprovided to a comparator; wherein the Inter-Integrated Circuit or PowerManagement Bus is configured to communicate protocols comprisinginstructions to perform at least one of: turn on or off the DC-DC powerconverter package, change a low power or sleep mode of the DC-DC powerconverter package, read out information about current settings of theDC-DC power converter package, read out diagnostic and/or technicalinformation about the DC-DC power converter package, set or change anoutput voltage provided by the DC-DC power converter package; wherein aPower Management Protocol is implemented as an interconnect layer on topof an Inter-Integrated Circuit implementation.

Some embodiments disclosed herein feature a power converter comprising:a printed circuit board (PCB) (the printed circuit board comprising: alower printed circuit board (PCB) part having a bottom side and a topside; and an upper printed circuit board (PCB) part having a bottom sideand a top side); embedded circuitry that is between the top side of thelower PCB part and the bottom side of the upper PCB part (the embeddedcircuitry comprising: a driver configured to generate one or more driversignals; and one or more switches configured to be driven by the one ormore driver signals), one or more vias extending through the upper PCBpart, and an inductor positioned over the top side of the upper PCBpart, wherein the one or more vias are electrically coupled to theinductor and to the embedded circuitry, and a footprint of the inductorat least partially overlaps a footprint of the embedded circuitry. Theembodiments can have any combination of: wherein the power converter isconfigured with an isolated topology configured to isolate a directelectrical connection between an input and an output of the powerconverter; wherein the isolation topology includes at least one of: aflyback topology, forward converter topology, two transistor forward,LLC resonant converter, push-pull topology, full bridge, hybrid,PWM-resonant converter, and half bridge topology; further comprising atransformer that includes a first inductor and a second inductorconfigured such that a changing current through the first inductorinduces a changing current in the second inductor; further comprising awireless communication system in a same package as the embeddedcircuitry; wherein an output of the power converter is configured to beadjusted in response to a wireless signal received by the wirelesscommunication system; further comprising a feedback system comprising aramp generator that is configured to generate a signal that emulates acurrent ripple through the inductor, and wherein the feedback systemincludes a current source that is configured to be trimmed or adjustedin response to a wireless signal received by the wireless communicationsystem; wherein the embedded circuitry comprises the wirelesscommunication system; further comprising a communication interfaceconfigured to receive a control signal for adjusting an output of thepower converter; wherein the communication interface includes a PowerManagement Bus (PMBUS); wherein the communication interface isconfigured to implement an inter-integrated circuit (I2C) protocol;further comprising a feedback system comprising a ramp generator that isconfigured to generate a signal that emulates a current ripple throughthe inductor, and wherein the feedback system is configured to trim theramp generator in response to a command received over the communicationinterface; wherein the embedded circuitry comprises a pulse widthmodulator (PWM) controller configured to generate one or more PWMsignals, wherein the PWM controller is coupled to the driver, andwherein the driver is configured to generate the one or more driversignals based at least in part on the PWM signals; wherein the inductorhas a current rating and the inductor has a saturation rating, andwherein the saturation rating is no more than 50% higher than thecurrent rating; wherein the inductor has a current rating and theinductor has a saturation rating, and wherein the saturation rating isno more than 20% higher than the current rating; further comprising anovercurrent protection circuit configured to prevent a current throughthe inductor from exceeding the saturation rating; further comprising anovercurrent protection circuit configured to cause at least one of theone or more switches to open in response to detecting an overcurrentcondition; wherein the power converter is a direct current to directcurrent (DC-DC) power converter; wherein the power converter is aalternating current to direct current (AC-DC) power converter; furthercomprising a feedback system, the feedback system comprising a currentsource, wherein the current source is configured to be trimmed oradjusted based at least in part in response to a wireless signalreceived by the wireless communication system; further comprising anovercurrent protection system configured to provide an indication of acurrent through the inductor, the overcurrent system comprising acurrent source, wherein the current source is configured to be trimmedor adjusted based at least in part in response to a wireless signalreceived by the wireless communication system

Some embodiments disclosed herein feature an article comprising: thepower converter of the above paragraph, a first system configured toperform a physical action using electrical power; and an electricalsystem configured to control the first system; wherein the powerconverter is configured to provide electrical power to one or both ofthe first system and the electrical system, and wherein the electricalsystem is configured to control the first system based at least in parton a wireless signal received by the wireless communication system thatis in the same package as the embedded circuitry of the power converter.In some embodiments, the article is an internet of things device. Someembodiments feature a power supply system comprising: a plurality ofpower converters, wherein each of the plurality of power converters isaccording to the power converter of the above paragraph; and a sharedpulse width modulator (PWM) controller configured to generate aplurality of PWM signals, wherein the PWM controller is coupled to thedrivers of the plurality of power converters to deliver the plurality ofPWM signals to the corresponding drivers of the power converters, andwherein the drivers are configured to generate the one or more driversignals based at least in part on the PWM signals. Some embodimentsfeature a power supply system comprising: a first power converteraccording to the power converter of Claim 1; and a second powerconverter coupled in parallel with the first power converter. The powersupply system can feature a control system configured to adjust anoutput of the first power converter and an output of the second powerconverter for current balancing.

Some embodiments disclosed herein feature a power converter comprising:a printed circuit board (PCB) comprising a lower printed circuit board(PCB) part having a bottom side and a top side and an upper printedcircuit board (PCB) part having a bottom side and a top side; an inputport configured to receive an input voltage; an output port configuredto provide an output voltage that is different than the input voltage;embedded circuitry that is between the top side of the lower PCB partand the bottom side of the upper PCB part, the embedded circuitrycoupled to the input port and configured to change the input voltage; avia extending through the upper PCB part; and an inductor or capacitorpositioned over the top side of the upper PCB part, wherein the one ormore vias are electrically coupled to the inductor or capacitor and tothe embedded circuitry, and wherein a footprint of the inductor orcapacitor at least partially overlaps a footprint of the embeddedcircuitry. The embodiments can have any combination of: wherein theinductor is positioned over the top side of the upper PCB part, whereinthe one or more vias are electrically coupled to the inductor and to theembedded circuitry, wherein a footprint of the inductor at leastpartially overlaps a footprint of the embedded circuitry, and whereinthe embedded circuitry comprises: a driver configured to generate one ormore driver signals and one or more switches configured to be driven bythe one or more driver signals; wherein the power converter is a directcurrent to direct current (DC-DC) converter; wherein the power converteris an alternating current to direct current (AC-DC) converter; furthercomprising a transformer that includes a first inductor and a secondinductor configured such that a changing current through the firstinductor induces a changing current in the second inductor; wherein theembedded circuitry comprises rectifier circuitry configured to change analternating current (AC) input voltage into a pulsed DC voltage;comprising smoothing circuitry configured to smooth the pulsed DCvoltage to a more stable DC voltage, wherein the smoothing circuitrycomprises the inductor or capacitor positioned over the top side of theupper PCB part; wherein the rectifier circuitry comprises one or moreswitches; wherein the rectifier circuitry comprises a diode bridge.

Some embodiments disclosed herein feature a direct current to directcurrent (DC-DC) power converter comprising: a lower printed circuitboard (PCB) part having a bottom side and a top side; an upper printedcircuit board (PCB) part having a bottom side and a top side; embeddedcircuitry that is between the top side of the lower PCB part and thebottom side of the upper PCB part, the embedded circuitry comprising: apulse width modulator (PWM) controller configured to generate a PWMsignal, a driver configured to receive the PWM signal and to generateone or more driver signals, a first switch configured to be driven by atleast one of the one or more driver signals, and a second switchconfigured to be driven by at least one of the one or more driversignals; one or more vias extending through the upper PCB part; aninductor positioned over the top side of the upper PCB part, wherein theone or more vias are electrically coupled to the inductor and to theembedded circuitry, and wherein a footprint of the inductor at leastpartially overlaps a footprint of the embedded circuitry; and a wirelesscommunication system in a same package as the embedded circuitry,wherein the wireless communication is configured to provide a signal toat least one of the PWM controller or the first switch to affect anoutput of the DC-DC converter.

Some embodiments disclosed herein feature a direct current to directcurrent (DC-DC) power comprising: an integrated circuit positionedinside of a printed circuit board (PCB), the integrated circuitcomprising: a first gallium nitride (GaN) switch configured to be drivenby a first signal from a driver; and a second GaN switch configured tobe driven by a second signal from the driver; an inductor positionedabove the integrated circuit such that the inductor has a footprint thatoverlaps, at least partially, with a footprint of the integratedcircuit; and a via electrically coupling the inductor to the GaN switch.Some embodiments can include: wherein the first GaN switch is an firstenhanced gallium nitride (eGaN) switch, and the second GaN switch is asecond eGaN switch.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example circuit level schematic of a chip embedded DC-DCconverter package.

FIG. 2 shows a package level schematic of an example embodiment of achip embedded DC-DC converter package.

FIG. 3 shows a cross section view of an example chip embedded DC-DCconverter.

FIG. 4A shows a perspective view of an example chip embedded DC-DCconverter with a stacked inductor.

FIG. 4B shows a reverse perspective view of an example rendered chipembedded DC-DC converter with a stacked inductor.

FIG. 4C shows a side view of an example chip embedded DC-DC converterwith an embedded stacked inductor.

FIG. 4D shows a side view of an example chip embedded DC-DC converterwith an embedded inductor.

FIG. 5 shows a see-through perspective view 500 of an example chipembedded DC-DC converter.

FIG. 6 shows a bottom view of an example chip embedded DC-DC converter.

FIG. 7A shows an example of a DC-DC converter used in a memory device.

FIG. 7B shows an example of a chip embedded DC-DC converter used in amemory device.

FIG. 8A shows an example application of DC-DC converters on a circuitboard.

FIG. 8B shows an example application of chip embedded DC-DC converterson a circuit board.

FIG. 9 shows a flowchart of an example method for making and using achip embedded DC-DC converter.

FIG. 10 shows an example dual inductor design for a dual buck converterusing a chip embedded DC-DC converter.

FIG. 11A shows a first example layout design for the embedded chip in adual buck converter.

FIG. 11B shows a second example layout design for embedded chips in adual buck converter.

FIG. 11C shows a third example layout design for embedded chips in adual buck converter.

FIG. 11D shows a fourth example layout design for embedded chips in adual buck converter.

FIG. 12 shows an example circuit level schematic of a dual buckconverter including a chip embedded DC-DC converter.

FIG. 13A shows an example circuit level schematic of a DC-DC converterincluding a chip embedded DC-DC converter.

FIG. 13B shows an example circuit level schematic of a DC-DC converterincluding a chip embedded DC-DC converter.

FIG. 14 shows an example chip embedded DC-DC converter with an externalripple voltage feedback circuit.

FIG. 15 shows example graphs of inductor current I_(L) over time andequivalent series resistance voltage V_(ESR) (also referred to as ripplevoltage) over time.

FIG. 16 shows an example chip embedded DC-DC converter with an externalripple voltage feedback circuit.

FIG. 17 shows an example chip embedded DC-DC converter with an internalripple voltage feedback circuit.

FIG. 18 shows an example circuit level schematic of a ramp generator.

FIG. 19 shows an method for shows an example method of making and usinga DC-DC converter.

FIG. 20 shows an example circuit level schematic of a chip embeddedDC-DC converter package with an isolated topology.

FIG. 21A shows an example DC-DC converter with a wireless communicationsystem in a package.

FIG. 21B shows an example DC-DC converter with a wireless communicationsystem in a package.

FIG. 21C shows an example package including a wireless communicationsystem and two DC-DC converters.

FIG. 21D shows and example wireless enabled power supply configured tocommunicate with an external wireless device.

FIG. 21E shows an example DC-DC converter with a wireless communicationsystem in a package.

FIG. 22 shows an example Internet of Things (IoT) device.

FIG. 23A shows an example DC-DC converter system including multipleDC-DC converters.

FIG. 23B shows an example DC-DC converter system including multipleDC-DC converters.

FIG. 24A shows a DC-DC converter with multiple power stages.

FIG. 24B shows an example layout of inductors in a DC-DC converter.

FIG. 25 shows an example side view of a DC-DC converter.

FIG. 26A shows an example block diagram of an AC to DC converter.

FIG. 26B shows an example AC to DC converter.

FIG. 26C shows an example AC to DC converter.

DETAILED DESCRIPTION Introduction

Direct current (DC) to direct current (DC-DC) converters are a type ofelectronic circuit. DC-DC converters can receive input power at a firstvoltage and can provide output power at a second voltage. Examples ofDC-DC converters include boost converters (which can have a higheroutput voltage than the input voltage), buck converters (which can havea lower output voltage than the input voltage), buck-boost converters,and various other topologies.

Some DC-DC converters are affected by non-ideal componentcharacteristics. These can include parasitic inductances, parasiticcapacitances, and/or parasitic resistances caused by components such aswire bonds and leadframe packages such as quad flat no-lead (QFN)packages, power quad flat no-lead (PQFN) packages, dual flat no-lead(DFN) packages, micro lead-frame (MLF) packages, etc. Furthermore,interconnections between internal components of the DC-DC converter,such as from a driver to switches, can also contribute to parasiticeffects. These parasitic effects can limit the switching speed and/orefficiency of DC-DC converters. The package can refer to the DC-DCconverter level package. The package can encapsulate one or more IC'sincluded in the DC-DC converter. The package can provide support andprotection for components in the DC-DC converter, and the package canprovide electrical contacts for connecting to the DC-DC converter. Invarious embodiments, the package may include one or more inductorsand/or capacitors within the package and/or coupled to the package fromthe outside.

This disclosure includes examples of highly integrated solutions wherethe DC-DC converter can switch more efficiently, switch at higherfrequencies, and/or offer improved performance with a reduced packagefootprint. An integrated circuit chip that integrates many DC-DCcomponents such as a pulse-width modulator controller, a driver, and/orone or more enhanced gallium arsenide switches (also known asenhancement mode gallium arsenide switches and eGaN FETs) can beincluded in a package. The integrated circuit can be embedded in aprinted circuit board, or embedded between printed circuit boards. Thepackage can include an inductor and/or capacitor in a vertical design toreduce the package footprint. Certain features can reduce the parasiticeffects that would otherwise prevent achieving higher switching speedsand/or higher efficiency. By efficiently achieving higher switchingspeeds, the inductor size can then be reduced. The DC-DC converter canoperate at higher frequencies, offer better transient performance, havelower ripples, use fewer capacitors, and/or reduce the overallfootprint.

For purposes of providing an introduction, certain aspects, advantages,and novel features have been introduced. It is to be understood that notnecessarily all such aspects, advantages, and novel features of theintroduction are achieved in accordance with any particular embodiment.Thus, one or more aspects, advantages, and novel features may beachieved without necessarily achieving the other aspects, advantages,and novel features disclosed herein. It is also to be understood thatnot all aspects, advantages, and novel features have been disclosed inthe introduction.

Example Schematic Diagram

FIG. 1 shows an example circuit level schematic of a chip embedded DC-DCconverter package 100. The schematic shows a power input port 101, apower source 103, an input capacitor 105, a ground port 106, ground 107,a voltage output port 109, an output capacitor 111, an integratedcircuit (IC) chip 113A, an alternative IC 113B, a driver 117, a pulsewidth modulator (PWM) controller 119, a first electric pathway 121, afirst switch (e.g., a first enhanced gallium nitride (eGaN) switch) 123,a second electric pathway 125, a second switch (e.g., a second eGaNswitch) 127, a third electric pathway 129, an inductor 131, and an ACbypass capacitor 133. A dotted line 135 indicates an alternative,separate packaging of the switches 123, 127. The switches 123, 127 canalso be referred to as power switches, switching FETs, and/or switchingtransistors. The schematic also shows a current source 137, a comparator139, and fault logic and/or over current protection circuitry 141.

The chip embedded DC-DC converter package 100 can be coupled through thepower input port 101 to the power source 103 and also coupled throughthe input capacitor 105 to ground 107. The chip embedded DC-DC converterpackage 100 can also include a voltage output port 109 that can becoupled through the output capacitor 111 to ground 107. The chipembedded DC-DC converter package 100 can also include the groundreference port 106 that is coupled to ground 107.

The chip embedded DC-DC converter package 100 can have a printed circuitboard (PCB) that includes an embedded integrated circuit (IC) chip 113Aor 113B. The IC can include a driver 117 and/or a pulse width modulator(PWM) controller 119. By way of example, the first electric pathway 121couples the IC to the gate of a first eGaN switch 123. The secondelectric pathway 125 couples the IC to the gate of the second eGaNswitch 127. The third electric pathway 129 couples the IC to a source ofthe first eGaN switch 123, a drain of the second eGaN switch 127, and tothe inductor 131. The inductor 131 can be coupled to the voltage outputport 109. An AC bypass capacitor 133 can be coupled from the drain ofthe first eGaN switch 123 to the source of the second eGaN switch 127 toshort AC signals to ground 107.

Although FIG. 1 shows the driver 117 and the PWM controller 119 as partof the IC 113A, in various embodiments, the IC can include one of thePWM controller 119 or the driver 117 while the other of the PWMcontroller 119 and the driver 117 is separately coupled to the IC 113A.In some embodiments, one of the eGaN switches 123, 127 or the pair ofeGaN switches 123, 127 can be integrated into the IC 113A along with therespective electric pathways 121, 125, and/or 129. The IC 113A can be asemiconductor. The IC 113A can be a silicon, gallium arsenide, galliumnitride, eGaN, or other III-V material based semiconductor. Accordingly,any integrated components, can also be made of a material the same as orsimilar to the IC 113A. The switches 123, 127, electric pathways 121,129, 125, driver, 117, and PWM controller 119 can also be made of thesame or similar material as the IC 113A.

The pair of switches 123, 127 can be monolithic eGaN field effecttransistors (FETs). In some embodiments, the pair of switches 123, 127can be separate devices, including two standalone eGaN FETs. In someembodiments, the switches 123, 127 are metal oxide field effecttransistors (MOSFETs). Various other numbers or types of switches can beused in various other embodiments. Although many embodiments describethe switches 123, 127 as eGaN switches, other suitable materials can beused instead of or in addition to eGaN.

In some embodiments, the electric pathways 121, 129, 125 can beimplemented with vias such as copper pillars, traces, and/or otherelectric pathways with low parasitic effects (e.g., low parasiticinductance, low parasitic resistance, and/or low parasitic capacitance).Wire bonds can have higher parasitic effects (e.g., higher parasiticinductance, higher parasitic resistance, and/or higher parasiticcapacitance).

The ports, including power input port 101, ground port 106, and voltageoutput port 109, can be implemented as pads, pins, or other electricconductor with low parasitic effects (e.g., low parasitic inductance,low parasitic resistance, and/or low parasitic capacitance). The portscan be designed to couple to traces on another device such as amotherboard, PCB, etc.

Many variations are possible. In some embodiments, bypass capacitor 133can be omitted. Some embodiments can feature different inductors,capacitors, magnets, and/or resonant arrangements. The variouscomponents shown in the example schematic of FIG. 1 form a DC-DCconverter, but DC-DC converters can have other variations. It will beappreciated that the teachings disclosed herein can extend to DC-DCconverters of other variations.

By way of example, the DC-DC converter 110 can receive a power signalthrough the power input port 101 from the power source 103. The powersignal can be filtered through shunt input capacitor 105 that can act asa decoupling capacitor to filter noisy alternating current (AC) signalcomponents. The power signal is provided to the drain of the firstswitch 123 of a pair of switches 123, 127.

A driver 117 provides a first control signal through the electricpathway 121 to the gate of the first switch (e.g., eGaN switch) 123. Thedriver also provides a second control signal through the electricpathway 125 to the gate of the second switch (e.g., eGaN switch) 127.Using the control signals, the driver can turn the switches 123, 127 onand off in alteration. The driver can control the signal such that theon/off state of the first switch 123 is opposite of the on/off state ofthe second switch 127. The on/off duty cycles of the control signals canbe set by the PWM controller 119. The PWM controller 119 can alsocontrol the pulse width or period through PWM signals provided to thedriver.

The switches 123, 127, IC 113A (e.g., including the PWM controller 119and/or driver 117), and the inductor 131 can be arranged to form part ofa non-isolated synchronous power converter or a power stage. When thedriver 117 drives the first switch 123 on and drives the second switch127 off, power can be provided from the power source 103 to an energystorage circuit, such as the inductor 131 and/or capacitor 111, causingthe DC output voltage at voltage output port 109 to increase. Whiledriver 117 drives the first switch 123 off and drives the second switch127 on, power from the energy storage circuit can drain through thesecond switch 127 to ground 107, causing the DC output voltage atvoltage output port 109 to decrease. Accordingly, the pair 123 ofswitches 123, 127 can be quickly toggled to control the DC outputvoltage at voltage output port 109. The inductor 131 and capacitor 111also act as a resonant filter that helps regulate the DC voltage.

The comparator 139 has a first input coupled to the drain of the secondswitch 127. The comparator 139 has a second input coupled to the sourceof the second switch 127. Accordingly, the comparator 139 can be coupledacross the second switch 127. In some embodiments, the comparator 139can have an inverting terminal as the first input. The first input ofthe comparator 139 can also be coupled to a current source 137. An I²Cand/or PMBUS (further described with respect to FIG. 2) can be used totrim and/or adjust the output current of current source 137.Accordingly, an overcurrent limit can be set and/or adjusted. The outputof the comparator 139 can be provided to fault logic and overcurrentprotection (OCP) circuitry 141.

The comparator 139 along with the fault logic and OCP circuitry 141 areconfigured to sense the drain-source resistance R_(ds) when the switch127 is on. The voltage drop across the switch 127 caused by R_(ds) iscompared to a reference value that can be adjusted by trimming oradjusting current source 137. The output of the comparator 139 can tripwhen an overcurrent condition occurs. The overcurrent protectioncircuitry 141 can turn off the switches 123, 127 and/or the driver whenan overcurrent condition is detected and enter fault mode. In variousembodiments, the OCP circuitry can couple directly to the gates of theswitches 123, 127 to turn off the switches, short one or morealternative energy pathways (not shown) to discharge energy, affect thePWM controller 119 outputs in response to an overcurrent condition,and/or affect the driver 117 outputs in response to an overcurrentcondition. In fault mode, the system can make periodic attempts torecover by briefly turn on the switches 123, 127 and/or driver, attemptto detect the overcurrent condition, and if the overcurrent conditionstill persists, turn off the switches 123, 127 and/or driver 117, andwait for a period of time before re-attempting to recover.

Sometimes, overcurrent conditions can occur as a result of inductorsaturation. An inductor, such as inductor 131, can saturate if too muchcurrent is provided to the inductor for too long and lose its magneticproperties. In such cases, the inductance of an inductor can drop by10%, 30%, or even more. A fully saturated inductor can effectively actas a wire, creating a potential short in the circuit. During saturation,the effective resistance of the inductor can drop, causing the outputcurrent to increase beyond specification and to potentially unsafelevels. The LC resonance of the circuit can also be affected when theinductor no longer effectively stores energy, so overvoltage and/orunder voltage conditions can occur.

The inductor 131 can be selected to tolerate the load current (DC outputcurrent) as well as an AC ripple. Accordingly, the saturation currentlimit of the inductor 131 can be selected to exceed a specified DCoutput current plus the maximum AC ripple. For example, if the chipembedded DC-DC converter generates a 10 A DC current and a +/−5 Aripple, then the maximum total current is 15 A, and the inductorsaturation limit should exceed 15 A. Inductors with higher inductancescan have higher saturation limits and be larger in size.

In some designs, determining the overcurrent protection limits anddetermining the inductor size can be determined independently from eachother, and one or the other can be over-engineered. This can occur, forexample, when a second party selects and couples inductors to a DC-DCconverter otherwise made by a manufacturer. In some cases, the secondparty may over-engineer the inductor out of an abundance of caution, forexample, by allowing for a 5 A AC current, a 10 A DC current, and a 100%DC overcurrent, such the inductor is selected to have a saturation limitof 25 A or more. In some cases, the second party may not know OCPlimits, and therefore resort to over-engineering the inductor to belarger in inductance and size such that the inductor is not saturated.In some cases, a second user could otherwise use a smaller inductor butfor overcurrent protection limits that are too high, and therefore usean inductor of a minimum size and inductance that are larger thanotherwise necessary. In some cases, a manufacturer may set anovercurrent limit too high or too low. Some embodiments of DC-DCconverters disclosed herein can include an adjustable overcurrent limit.Some embodiments of DC-DC converters disclosed herein can include bothovercurrent protection circuitry and an inductor, wherein theovercurrent limit is determined based at least on the size of theinductor, and the overcurrent limit can be set to a value equal toand/or below the saturation limit of the inductor. Some embodiments ofDC-DC converters disclosed herein can include both overcurrentprotection circuitry and an inductor, wherein the size of the inductoris selected, based at least in part, on the overcurrent limit, such thatthe saturation limit of the inductor is equal to or exceeds theovercurrent limit by a narrower margin such as 50% or less, 40% or less,30% or less, 20% or less, 10% or less, or any values therebetween, orranges bounded by any of these values, etc. Some embodiments of DC-DCconverters disclosed herein can have overcurrent limits set to be lessthan the expected maximum AC current plus twice the expected DC current,such as a 90% or less DC overcurrent, a 75% or less DC overcurrent, a50% or less DC overcurrent, 50% or less DC overcurrent, 40% or less DCovercurrent, 30% or less DC overcurrent, 20% or less DC overcurrent, 10%or less DC overcurrent, or any values therebetween, or ranges bounded byan of these values, etc. In some embodiments, a single designer canprovide the components for and select the values for both the OCPcircuit and limits as well as the inductor and its saturation limit.Accordingly, in some embodiments, the DC-DC converter can operatewithout the inductor reaching saturation while having a smallerfootprint, lower inductor direct current resistance, and increasedefficiency.

Packaging

FIG. 2 shows a package level schematic of an embodiment of a chipembedded DC-DC converter package 100. The chip embedded DC-DC converterpackage can include input port 101, ground port 106, and output port109. As described with respect to FIG. 1, a power input port 101 can becoupled to a power source 103, such as by way of an input capacitor 105that is coupled to ground. A voltage output port 109 can supply a DCoutput voltage to a load coupled at node 201, such as by way of anoutput capacitor 111 that is coupled to ground 107. An enable port 205is configured to receive a signal to enable the DC-DC converter. A testport 203 can be used to check the status of the device. In someembodiments, an Inter-Integrated Circuit (I²C) and/or Power ManagementBus (PMBUS) provides a communication pathway to/from the chip embeddedDC-DC converter package 100.

The package 100 footprint can include all the components of a DC-DCconverter. In some embodiments, the package 100 footprint includes theIC 113A or 113B and an inductor 131, for example such that the packagecan operate as a DC-DC converter without additional external inductors.In some embodiments, at least one or more of capacitors 105, 111, and/or133 can also be included within the package footprint, for example suchthe package can operate as a DC-DC converter without additional externalcapacitors.

In some embodiments, the I²C and/or PMBUS can be used to receive I²Cand/or PMBUS protocol communications to perform one or more of thefollowing: turn on or off the chip embedded DC-DC converter package 100,change a low power or sleep mode of the DC-DC converter package 100,read out information about current settings of the DC-DC converterpackage 100, read out diagnostic and/or technical information about theDC-DC converter package 100, set or change an output voltage provided bythe DC-DC converter package 100 (e.g., by changing a digital signalprovided to the digital to analog controller “DAC” described withrespect to FIG. 16 and FIG. 17), trimming a property of the rampgenerator (e.g., the ramp generator of FIG. 17) such as amplitude orfrequency, trimming one or more current sources (e.g., the currentsources of FIG. 18), and other functions. In some embodiments, the PMBUSprotocol is implemented as an interconnect layer on top of the I²Cimplementation.

Integration and Chip Embedded Design

The DC-DC converter can be highly integrated and can switch at higherfrequencies and offer improved performance as compared to other DC-DCconverters. In some designs, parasitic effects prevent can prevent DC-DCconverters from efficiently operating at higher frequencies (higherswitching speeds), if at all. A number of designs for DC-DC convertersare disclosed herein along with additional designs with reducedparasitic effects.

Some DC-DC converter packages include wire bonds and/or leadframepackages. An example 1 mΩ, 1 mm long bond wire may have 0.7 nH ofparasitic inductance, 0.08 pF of parasitic capacitance, and 140 mΩ ofparasitic resistance. Similar or higher parasitic effects can resultfrom leadframe packages such as quad flat no-lead (QFN) packages, powerquad flat no-lead (PQFN) packages, dual flat no-lead (DFN) packages,micro lead-frame (MLF) packages, etc. Some embodiments of DC-DCconverters disclosed herein can limit or avoid the use of wire bondsand/or leadframes altogether in order to reduce parasitic effects. Vias,traces, bumps, and/or bump pads can be used inside of a package instead.

Some DC-DC converter packages do not include an inductor or capacitor.Such packages give a user the flexibility to select particular valuesfor the capacitors and inductors and control the quality of thosecomponents. The DC-DC converter package, inductors, and capacitors maybe surface mounted on a motherboard or separate PCB and coupled togetherwith wire bonds or long traces through the motherboard or the separatePCB (for example, as shown in FIG. 7A). However, coupling a DC-DCconverter package to the external inductors or capacitors can introduceparasitic effects. Parasitic effects can similarly be introduced betweenthe inductor and a load. Some embodiments of DC-DC converters disclosedherein can reduce parasitic effects of coupling to the inductor orcapacitor by integrating the inductor or capacitor in the same packageas the other components of the DC-DC converter. In some embodimentsdisclosed herein, the electric pathways coupling to the inductors orcapacitors can be implemented with vias and/or traces instead of wirebonds. In some embodiments disclosed herein, the electric pathwayscoupling to the one or more inductors or capacitors can include viasand/or traces located in the PCB of the DC-DC converter instead ofincluding traces in the motherboard or separate PCB (e.g., as shown inFIG. 3 and FIG. 7B). In some embodiments disclosed herein, anycombination of the PWM controller, driver, inductor(s), capacitor(s),and/or switch(es) can be included in the same package.

In some designs, parasitic effects can arise as a result of componentinterconnections. For example, with respect to FIG. 1, a driver 117 inone integrated circuit 113A can couple to a separate electroniccomponent 135 that includes switches 123, 127. The integrated circuit113A and the separate electronic component 135 can be included in a PCB.The electric pathways 121, 129, 125 between the driver and the switches123, 127 can be implemented using traces on the PCB, but the traces on aPCB can have relatively higher parasitic effects as compared to electricpathways inside integrated circuits. Some embodiments of DC-DCconverters disclosed herein can reduce parasitic effects ofinterconnections between the driver and switches by integrating theswitches 123, 127, and driver 117 along with their interconnections inthe same IC 113B. In some embodiments disclosed herein, the PWMcontroller, driver, and switches are all included in the same IC 113B.In some embodiments, one or more capacitors can also be include in thesame IC 113B.

In some designs, MOSFET switches can be used. However, MOSFET switchescan be less efficient at higher switching speeds. In some embodimentsdisclosed herein, the switches 123, 127 can be eGaN switches. eGaNswitches can switch more efficiently and at higher speeds compared toMOSFET switches.

The synergy of the techniques disclosed herein will be appreciated.Parasitic capacitance and/or inductance effects can limit maximumswitching speeds in a DC-DC converter. This may be because the parasiticeffects can cause undesired energy to be stored, affecting the chargingand discharging of energy, and thereby affecting DC voltage regulation.The parasitic effects can also cause the switches to turn on or offslowly. In some embodiments, a combination of the techniques disclosedherein can cause the parasitic effects to be reduced by a sufficientdegree for improvement in DC-DC converter performance. Additionalsynergies relating to the arrangement, size, and performance of DC-DCconverters are also discussed in later sections of the detaileddisclosure.

Compared to some other DC-DC converters, some embodiments disclosedherein remove about 40 bond wires, which can reduce parasitic effects byabout 20 mΩ and can also reduce the package leakage inductance(parasitic inductance) by 10 nH or more. The elimination of theseparasitic effects can help to realize the benefits of high speedswitches (e.g., eGaN switches).

The figure of merit for a power switch can be determined according toequation 1:

$\begin{matrix}{{FOM} = {R_{{DS}{({ON})}}*Q_{G}}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$

where FOM is the figure of merit, R_(DS(ON)) is the on-resistance of theswitch, and Q_(G) is the gate charge of the switch. The gate chargeQ_(G) can be affected by parasitic inductances. Reducing the parasiticinductances can result in a lower FOM, a design improvement that isusually difficult to achieve.

It will be further appreciated that some, but not all, of the fulladvantages can be realized only by the simultaneous combination ofsufficient parasitic effect reduction and component choices. Forexample, some advantages of reducing parasitic effects may not berealized if MOSFETs are used, under some circumstances. This is because,although parasitic effects may be reduced to a sufficient level to allowfaster switching speeds, the MOSFET design may not allow for efficientswitching at the faster speeds. Likewise, the full switching potentialof eGaN switches (or other faster, and typically more costly switches)in a DC-DC converter can be limited by parasitic effects. Full switchingpotential can include more efficiently switching at higher frequenciesin the megahertz range such as 1 MHz or higher, 3 MHz or higher, 4 MHzor higher, 5 MHz or higher, 7 MHz or higher, 10 MHz or higher, etc. Insome instances, switching rates up to 15 MHz can be achieved, andswitching rates outside these identified ranges could be used in someimplementations.

Accordingly, an engineer testing limited techniques to reduce parasiticeffects may not cause the parasitic effects to drop to an impactfullevel. An engineer testing a combination of parasitic reductiontechniques may not achieve more significant gains if switching speedsare limited by MOSFETs. An engineer testing eGaN switches without firstrealizing and addressing the parasitic effects in DC-DC converters maynot realize the switching speed benefits of using eGaN switches,especially because eGaN switches can be more costly than MOSFETswitches. Additionally, increasing the switching speeds, especially to1, 2, 3, 5, 7 or 10 MHz and above, depending on other variables, can goagainst conventional knowledge that efficiency tends to decrease withhigher switching speeds.

The Integration and Chip Embedded Design section of the DetailedDisclosure discusses various embodiments for reducing parasitic effectsand/or achieving faster switching speeds. Although some embodimentsinclude a combination of features, the embodiments including fewer thanall the features will still be appreciated in their own right.

Physical Arrangement Figures

FIG. 3 shows a cross section view 300 of an example chip embedded DC-DCconverter. The view 300 includes insulators 301, conductor (e.g., metal)303, bumps or pads 304, conductor micro-vias 305, a first PCB layer 307,conductive plating 309, a PCB core 311, traces 313, an embedded IC chip315, a second PCB layer 317, an inductor 321, and a capacitor 323.

The embedded IC chip 315 can be embedded in a PCB core 311. In variousembodiments, the IC chip 315 can be embedded in a layer of the PCB orbetween two or more layers of a PCB, or between a lower PCB and an upperPCB. The embedded IC chip 315 can include a PWM controller, driver,and/or one or more switches (e.g., eGaN switches), as discussed herein,such as with respect to FIG. 1. The embedded IC chip 315 can be coupledto the inductor 321 and capacitor 323 through a plurality of vias 305and/or traces 313 in a DC-DC converter arrangement.

The insulators 301 can include, for example, a solder mask, mold,underfill, etc. The layers 307, 317 of the PCB can be a PCB substrate,laminate, resin, epoxy, insulator, etc. In the illustrated view 300shown in FIG. 3, PCB core 311 can be a filler, laminate, an insulatingmold compound or substrate, etc. The conductor (e.g., metal) 303, vias305, and traces 313 can be metals or conductive materials of varioustypes, such as copper, aluminum, gold, etc. Although the vias are shownas plated vias, some embodiments can use pillars or other vias. Variousembodiments can use more or fewer types and layers of metals.

In some embodiments, the IC chip 315 can be flip chip mounted. Invarious embodiments, the IC chip 315 can be face up or face down suchthat connections on the IC chip 315 can be facing toward the inductor321 and/or capacitor 323 or away from the inductor 321 and/or capacitor323. If the connections on the IC chip 315 face away from the inductor321 and/or capacitor 323, then the inductor 321 and/or capacitor 323 canbe coupled by way of vias 305 and/or traces 313 to the far side of theIC chip 315.

Although FIG. 3 shows a single IC chip 315 that can include a driver andswitches, in some embodiments, switches (e.g., monolithic eGaN switches)can be chip embedded in the PCB separate from the IC chip 315 and can beinterconnected with the driver in the chip embedded IC chip 315. Vias,pads, and/or traces can couple various components as a DC-DC converter,and the two dies can be faced down or up. An inductor or other magneticcan be placed in or on the top layer and create a complete half bridgecombination in a Buck converter or any other configuration using a HalfBridge scheme.

Although the IC chip 315 is shown coupled to the inductor 321 by way ofboth vias 305 and traces 313, in some embodiments, the IC chip 315 canbe coupled to the inductor 321 and/or capacitor 323 by either vias 305or traces 313 without the other. In various embodiments, the PCBassembly can have more or fewer PCB layers than shown in FIG. 3, and theIC chip 315 can be embedded in or between a single layer or multilayerPCB. In various embodiments, layers 307, 317 can be layers of a PCB orseparate PCBs. The metal 303 exposed at the bottom of the PCB canprovide input/output pads for coupling to an input power supply, aground, and/or a load.

Parts of the inductor 321 and/or capacitor 323 can be stacked above theIC chip 315. In some embodiments, the inductor 321 and/or the capacitor323 can be stacked entirely over the IC chip 315. The inductor 321 andIC chip 315 tend to be the larger components in the DC-DC converterpackage. In some embodiments, the smaller of the inductor 321 or IC chip315 can be stacked within the footprint of the larger of the inductor321 or IC chip 315. Although a single IC chip 315 that includes bothswitches and a driver is shown in FIG. 3, in various embodiments, theinductor 321 and/or capacitor 323 can overlap, at least partially, withcomponents that are separate from the single IC chip 315. For example,the inductor 321 can overlap with one or more switches, with the PWMcontroller, and/or with the driver, etc.

The position of inductor 321 can contribute to better thermalperformance of the DC-DC converter. By positioning the inductor 321 ontop, the inductor 321 can be cooled by ambient air. The top-mountedinductor 321 also allows various sizes or shapes for the inductor 321 tobe used (e.g., such that the inductor 321 is not constrained by thedimensions of the PCB).

FIG. 4A shows a perspective view 400 of an example chip embedded DC-DCconverter with a stacked inductor 321. The inductor 321 can be stackedabove an IC chip (not visible) that is embedded in a core 311 betweenthe layers 317, 307 of a PCB. The inductor 321 can be coupled to thePCB, at least partially, through a metal contact 401. In someembodiments, one or more capacitors 323 (not visible) can be coupled tothe PBC layer 317.

FIG. 4B shows a reverse perspective view 425 of an example rendered chipembedded DC-DC converter with a stacked inductor 321. The inductor 321can be stacked above an IC chip (not visible) that is embedded betweenthe layers 317, 307 of a PCB. The inductor 321 can be coupled to thePCB, at least partially, through a metal trace 313. One or morecapacitors 323A, 323B can be coupled to the PBC layer 317. The one ormore capacitors 323A, 323B can also be coupled to inductor 321 by way ofa trace 313.

In some embodiments, as switching frequencies increase, inductors can bemade smaller. Additionally, some materials and technologies such as thinfilm technologies can also reduce the sizes of inductors. Accordingly,in some embodiments the inductor can be embedded in a PCB, such as aboveor alongside an IC. Such arrangements offer further integration andincrease the amount of space available, such as on a PCB mountingsurface area, for other peripheral components, such as input and outputcapacitors.

FIG. 4C shows a side view 450 of an example chip embedded DC-DCconverter with an embedded stacked inductor. A first layer 451 can be,for example, a packaging layer or a PCB layer. A second layer 453 can bea PCB layer that includes an inductor embedded within the second layer453. A third layer 455 can be a PCB layer that includes circuitry (e.g.,an IC) embedded within the third layer. The circuitry (e.g., the IC) caninclude, for example, the PWM controller, driver, and/or switches (e.g.,FET's). A fourth layer 457 can be, for example, a packaging layer or aPCB layer. In FIG. 4C, the inductor can overlap, at least partially,with the circuitry (e.g., IC) or be off to the side. The inductor cancouple to the IC by way of vias and/or traces without bond wires.

FIG. 4D shows a side view 475 of an example chip embedded DC-DCconverter with an embedded inductor. The layers 451, 453, 455, and 457can be the same as or similar to those described for FIG. 4C. In FIG.4D, layer 455 can include circuitry (e.g., the IC) and the inductorbeside the other circuitry (e.g., the IC). The IC can be coupled to theinductor by way of traces. Layer 453 can include embedded capacitors. Insome embodiments, the one or more embedded capacitors can be embedded inthe PCB, and the embedded capacitors can be mounted so that a footprintof the one or more embedded capacitors overlaps a footprint of thecircuitry (e.g., the IC) and/or inductor. In some embodiments, one ormore embedded capacitors can be included in the same layer 455 with theembedded circuitry (e.g., the IC) and/or the embedded inductor. In someembodiments, capacitors can be surface mounted on layer 453. In someembodiments, layer 453 can be omitted. In some embodiments, capacitorscan be mounted outside the PCB (e.g., such as capacitor 323 shown inFIG. 3). Many variations are possible. Circuitry (e.g., one or moreIC's) including any combination of the PWM controller, driver, and/orswitches can in the same layer as either or both of the one or moreinductors and/or the one or more capacitors. The IC can be an eGaN IC. Amonolithic eGaN IC can include any combination of the PWM controller,the driver, and the one or more switches. In some implementations, theone or more capacitors and/or the one or more inductors can be includedin an IC (e.g., an eGaN IC) together with one or more of the PWMcontroller, the driver, and/or the one or more switches. The one or moreinductors, the one or more capacitor, or both can be disposed in aseparate layer embedded in the PCB, such as either above or below thecircuitry (e.g., the IC). In some embodiments, the one or more inductorscan be on a first side of the circuitry (e.g., the IC) and the one ormore capacitors can be on a second opposing side of the circuitry (e.g.,the IC). In some embodiments, the one or more inductors and the one ormore capacitors can be embedded in different layers of the PCB but onthe same side of the circuitry (e.g., the IC). Either or both of the oneor more capacitors and/or the one or more inductors can be disposedoutside the PCB (e.g., as in FIG. 3). In some implementations, one ormore of the PWM controller, driver, and one or more switches can be indifferent layers embedded in the PCB. In some embodiments, the PWMcontroller and the driver can be in separate ICs (e.g., eGaN ICs).Components embedded in different layers in the PCB can be oriented sothat they at least partially, or completely, overlap, or so that they donot overlap. Any eGaN embodiment disclosed herein can alternatively beimplemented as a GaN embodiment, which can include depletion mode GaN,eGaN and/or any combination thereof.

FIG. 5 shows a see-through perspective view 500 of an example chipembedded DC-DC converter. FIG. 5 shows the same example chip embeddedDC-DC converter as shown in FIG. 4A and FIG. 4B, but with without theinductor 321, capacitors 323, or core 311 to illustrate otherwiseobscured components. Vias 305 can couple traces 313 and/or pads 303.

FIG. 6 shows a bottom view 600 of an example chip embedded DC-DCconverter. FIG. 6 shows the same example chip embedded DC-DC converteras shown in FIG. 5. Exposed metal 303 pads between areas of insulator301 provide electrical contacts for the supply voltage, ground, and/orvoltage output. Vias 305 are shown. However, in some embodiments, thevias do not visibly extend through the exposed metal 303.

Reduced Footprint

The physical arrangement and other techniques disclosed herein can beused to reduce the footprint of a DC-DC converter. In some embodiments,the footprint can be reduced by about 70%. Stacked components, the useof smaller inductor with faster switching speeds, and a single packageof components can all contribute to the reduced footprint.

As previously discussed, some DC-DC converter packages do not include aninductor or capacitor, and some DC-DC converters may include an inductormounted beside a driver, PWM controller, and/or IC chip. Such packagesmay give a user the flexibility to select particular values for thecapacitors and/or inductors and control the quality of those components.However, arranging components in a stacked arrangement instead of besideeach other can reduce the footprint of the DC-DC converter. Someembodiments disclosed herein feature an inductor that is verticallystacked, wholly or partially, above the IC chip. Some embodimentsdisclosed herein feature a capacitor that is vertically stacked, whollyor partially, above the IC chip. Stacking the inductor and/or capacitorcan reduce the footprint of the DC-DC converter. Stacked components canbe electrically coupled (e.g., to the IC chip) with vias, which canreduce parasitic effects as discussed above. Some embodiments disclosedherein can provide for ease of design such that individual components donot need to be selected, arranged, and mounted by a user. A singlepackage DC-DC converter can be used without configuring externalcapacitors or inductors. Furthermore, some embodiments can integrate theinductor into the package without compromising the size of the inductor,without compromising the performance of the inductor, and/or withoutrequiring a custom made inductor.

As discussed above, the parasitic effects can be reduced, and theswitching speed of the DC-DC converter can be increased with efficiency.The inductance of a DC-DC converter can be determined according toequation 2,

$\begin{matrix}{L = \frac{( {{Vin} - {Vo}} )*{Vo}}{2\Delta\;{iL}*{Fs}*{Vin}}} & {{Eq}.\mspace{14mu} 2}\end{matrix}$

where L is the inductance, V_(in) is the input voltage, V_(o) is theoutput voltage, ΔiL is the inductor ripple current, and F_(s) is theswitching frequency. Notably, the inductance decreases as the switchingspeed increases. Accordingly, reduced parasitic effects and faster oneor more switches (e.g., eGaN switches) can allow the DC-DC converters touse smaller inductors. In DC-DC converters, inductors can be one of thelargest components. By reducing the size of the inductor (e.g., to afraction of its original size), the footprint can be substantiallyreduced.

Some DC-DC converters include multiple packages. For example, theremight be a first package that includes a driver, a second package forswitches, and a third package that includes an inductor. Someembodiments disclosed herein feature a single package that includes allof the components of a DC-DC converter, such as a PWM controller,driver, switches (e.g., eGaN switches), inductor(s), and capacitor(s).In some embodiments disclosed herein, a number of components can beintegrated into a single IC, such as the PWM controller, driver, and/orswitches (e.g., eGaN switches).

Accordingly, the features relating to higher switching speeds canadditionally synergize with the physical design of a DC-DC convertersuch that the size of a DC-DC converter can be reduced. The smallerDC-DC converter can be used in various applications to provide highercurrent density to power modern electronic devices such asmicroprocessors, field programmable gate arrays, application specificintegrated processors, etc. Smaller DC-DC converters can be made atreduced manufacturing costs. The techniques disclosed herein can reduceboard and package parasitic effects. Smaller DC-DC converters canfeature tighter connections that reduce parasitic effects between theinductor, the IC chip, and/or a load, and the DC-DC converter can beefficiently operated at higher frequencies. The techniques disclosedherein can lead to reduced noise, including lower ripple effects andlower electromagnetic interference.

Generally, a larger sized DC-DC converters can handle larger amounts ofcurrent. In some embodiments, the DC-DC converters disclosed herein canhandle a given amount of current with a smaller sized DC-DC converter,as compared to conventional approaches. For example, the DC-DCconverters disclosed herein can have a footprint area of less than 20mm² per amperage of current, less than 15 mm² per amperage of current,less than 10 mm² per amperage of current, less than 7 mm² per amperageof current, less than 5 mm² per amperage of current, less than 4 mm² peramperage of current, less than 3 mm² per amperage of current, less than2 mm² per amperage of current, less than 1.5 mm² per amperage ofcurrent, or less than 1 mm² per amperage of current. The DC-DCconverters can have as low as 1.0 or 0.5 mm² per amperage of current,although values outside the ranges discussed herein can be used in someimplementations.

Example Applications

The DC-DC converters disclosed herein can be used to provide power toelectronic devices. Examples include using the DC-DC converter toconvert a primary supply voltage into a DC voltage appropriate forelectronic devices powered through the supply voltage. By way ofexample, in some applications, modern power management solutions can use40 or more chip embedded DC-DC converters to power 40 or more electroniccomponents while meeting specifications for size, input/output ripple,efficiency, and thermal limits. DC-DC converters as disclosed herein canbe made smaller and used in modern systems where the space and boardsize are limited. DC-DC converters as disclosed herein can be used topower components in various market segments such as storage, servers,networking, telecom, internet of things, etc. Other applications includeusing the DC-DC converters disclosed herein to provide power to micropoint of load devices such as for processors in blade servers,components of solid state devices, etc.

FIG. 7A shows an example of a DC-DC converter used in a memory device700. The memory device 700 can be, for example, a solid state drive. Thememory device 700 can include a controller 703 and a plurality of memorychips 705 coupled through a PCB 701. A DC-DC converter 707 can receive asupply voltage through power input pins 709 and provide DC power to thememory chips 705 and/or controller 703. The DC-DC converter 707 can becoupled to an inductor 709 by way of bond wires or traces 711 throughthe PCB 701. The PCB 701 can be a separate PCB 701 from the package ofthe DC-DC converter 707. The capacity of the memory device 700 islimited by the number of memory chips 705, which is six memory chips inthe implementation of FIG. 7A.

FIG. 7B shows an example application of a chip embedded DC-DC converterto a memory device 750. A chip embedded DC-DC converter 751 receives asupply voltage through power input pins 709 and provide DC power to thememory chips 705 and/or controller 703. A smaller inductor can beincluded in the package footprint of the chip embedded DC-DC converter751. The chip embedded DC-DC converter 751 can be substantially smallerthan the DC-DC converter 707 of FIG. 7A. Accordingly, the additional PCBroom can be used for an additional memory chip 753 to improve the memorycapacity of the memory device 750.

FIG. 8A shows an example application of DC-DC converters on a circuitboard 800. The circuit board 800 can be, for example, a blade server ormotherboard that includes a plurality of power connectors 801 (PWR), avoltage regulator management (VRM) circuit 803, a plurality of randomaccess memory (RAM) slots 805, a plurality of peripheral componentinterconnect express (PCIE) slots 813, and a rear input/output panel815. The circuit board 800 also includes a plurality of DC-DC converters807 at points of load. The DC-DC converters 807 each power one of thecentral processing units 809 or computer chips 811. The DC-DC converters807 can receive power supplied through the power connectors 801 and/orVRM circuit 803 and convert the voltage of the supplied power into a DCvoltage meeting the DC power specifications of each respective CPU 809or computer chip 811.

FIG. 8B shows an example application of chip embedded DC-DC converterson a circuit board 850. The circuit board 850 includes a plurality ofchip embedded DC-DC converters 851 (e.g., at points of load). The chipembedded DC-DC converters 851 can power central processing units 809and/or computer chips 811, for example. The DC-DC converters 851 canreceive power supplied through the power connectors 801 and/or VRMcircuit 803 and convert the voltage of the supplied power into a DCvoltage meeting the DC power specifications of the respective CPUs 809and/or computer chips 811. The chip embedded DC-DC converters 851 can besmaller than the DC-DC converters 807 of FIG. 8A. Accordingly, themotherboard can have room for additional computer chips 853. Areaspreviously occupied by the DC-DC converter 807 may now be open areas 855available for other components or can be left open to improve airflow.

Additional Embodiments

In some example embodiments, one or more switches (e.g., eGaN switches)(e.g., monolithic or standalone) can be used in a chip embedded DC-DCsynchronous buck converter with an inductor where the embedded IC chipincludes a PWM controller and a driver. In comparison to a MOSFET basedDC-DC synchronous buck converter, the chip embedded DC-DC converter canbe switched at higher speeds with lower switching losses, can switchmore efficiently at high switching speeds (e.g., around 5 MHz or atother speeds described herein), and the eGaN switches can have aboutfive times lower Q_(G).

Some embodiments realize improved efficiency gains of about 30% lowerpower losses in comparison to alternative designs when switching at thesame speeds, such as 3 MHz.

An example embodiment of a chip embedded DC-DC converter can be packagedin about a 3×3×1.5 mm package, switch at ranges from about 1-5 MHz, andsupply about 6 A of current. In comparison, various wire-bond DC-DCconverter designs for similar amperage can be about 12×12 mm in area andswitch at about 600 kHz.

An example embodiment of a chip embedded DC-DC converter can receive a12 V power supply and output a DC signal that is about 1.2 V and about10 A. The chip embedded DC-DC converter can switch at about 1 MHz andinclude an inductor that is about 300 nH.

Some example embodiments of a chip embedded DC-DC converter include 25 Abuck converters that can fit in package that is about 6×6 mm or 7×7 mm.

Some embodiments of chip embedded DC-DC converters include eGaNswitches. The switches can operate at about 5 MHz, and the chip embeddedDC-DC converters can operate with efficiency similar to MOSFET basedDC-DC converters operating at about 1 MHz. This can result in smallerpackage sizes and overall higher system performance due to fasterresponses to transient loads.

Example Method

FIG. 9 shows a flowchart of an example method 900 for making and using achip embedded DC-DC converter.

At block 901, an integrated circuit can be fabricated. The integratedcircuit can be an IC chip that includes at least one of: a driver, a PWMcontroller, and one or more power switches. The IC chip can include aplurality of: a driver, a PWM controller, power switches, an inductor, acapacitor, or other component of a DC-DC converter. In some embodiments,the one or more power switches can be eGaN switches, gallium arsenideswitches, or other types of high performance switch.

At block 903, a first PCB part can be formed. Forming the first PCB partcan include providing a PCB layer or insulator, masking, etching,drilling vias, filling vias, depositing conductive traces and pads,providing some or all of the I²C and/or PMBUS, and the like.

At block 905, the IC chip can be embedded using chip embeddedtechnology. In some embodiments, a cavity could be formed (e.g., in aPCB), for example using machining or etching techniques, and the IC chipcould be placed into the cavity. The IC chip can be coupled to the firstPCB part, into a PCB, on a PCB layer, between multiple PCB layers,between multiple PCBs, etc. The IC chip can be chip embedded face up orface down. In some embodiments, the IC is embedded using a flip chiptechnique. The IC chip or die can be coupled to a die attachment orbonding material. In some embodiments, other components can also beembedded in the PCB. For example, in embodiments where one or moreswitches (e.g., monolithic eGaN power switches) are separate from the ICchip, the one or more switches (e.g., monolithic eGaN switches) can alsobe embedded in the PCB.

At block 907, the insulators and conducive routing for a second part ofthe PCB can be formed. This can include providing an additional PCBlayer or insulator, masking, etching, drilling or exposing vias, fillingvias, depositing conductive traces and pads, providing some or all ofthe I²C and/or PMBUS, and the like. In some embodiments, the actionsdescribed with respect to blocks 903, 905, and 907 be integratedtogether and/or overlap. In blocks 903, 905, and 907, the conductors(e.g., vias and traces) can be formed to couple components in a DC-DCconverter arrangement (e.g., as shown in FIG. 1 and FIG. 3).

At block 909, an inductor can be coupled. The inductor can be coupled tothe top of the PCB. The inductor can be stacked, at least partially,with one or more of the other components of the DC-DC converter such asthe IC chip. The inductor can be stacked, at least partially, with oneor more of the other components of the DC-DC converter such as the PWMcontroller, driver, and switches. In some embodiments, other surfacecomponents such as capacitors can also be coupled. Accordingly, thecomponents of a chip embedded DC-DC converter can be coupled together.In some embodiments, the inductance of the inductor can be selectedbased at least in part on an overcurrent limit, for example, asdescribed with respect to FIG. 1. In some embodiments, an overcurrentlimit can be determined, adjusted, and/or trimmed based at least in parton a saturation limit of the inductor. In some embodiments, the inductorand overcurrent limit values can be determined and/or designed by asingle person, designer, design team, and/or manufacturer.

At block 911, the chip embedded DC-DC converter can be packaged. Thiscan include packaging the chip embedded DC-DC converter as a singlediscrete component. The package can include the inductor and capacitorsuch that the DC-DC converter can operate without external inductors orcapacitors.

At block 913, a load can be coupled to the DC-DC converter. This caninclude, for example, coupling an output of the packaged chip embeddedDC-DC converter through a trace on a separate motherboard to anelectronic device. In some embodiments, the DC-DC converter can becoupled near the point of load to reduce some parasitic effects.

At block 915, a power supply can be coupled to the packaged chipembedded DC-DC converter. Accordingly, the chip embedded DC-DC convertercan use the supplied power to provide a DC output voltage to power theelectronic device.

Although blocks 911, 913 describe packaging and using the packaged chipembedded DC-DC converter with a separate PCB of a load device, in someembodiments, the techniques described herein can be applied to theend-device PCB.

Multi-Inductor Chip Embedded DC-DC Converter

The chip embedded DC-DC converter technology described herein can beextended to multi-inductor implementations. This can include, forexample, dual buck converters, dual boost converters, and voltageconverters with 2, 3, 4, 5, 6, 8, 16, or any number of inductors. Themultiple inductors can be arranged in parallel. The output of themultiple inductors (e.g., in parallel arrangement) can be coupled to anenergy storage circuit such as a capacitor or LC resonant circuit. Eachrespective inductor can be coupled to a respective pair of switches.Each respective pair of switches can be driven by a respective driver.Each driver can be driven with PWM signals that are out of phase withPWM signals provided to the other drivers. Each PWM signal can have anon time that is a small enough fraction of a shared period such that thesuperimposed combination of driver signals has an effective period thatis shorter than the shared period. In some embodiments, themulti-inductor chip embedded DC-DC converter can be formed byduplicating some or all of the components (e.g., the switches, theinductor, parts of the integrated circuit) disclosed herein (e.g., shownin FIG. 1).

The various embodiments disclosed herein can have one, somecombinations, or all of the following features. Multi-inductor chipembedded DC-DC converters can operate faster and more efficiently thansingle inductor chip embedded DC-DC converters. The current through theDC-DC converter can be divided among the multiple inductors. The heatcan be spread out over multiple inductors. Smaller sized individualinductors can be used. The current density can be increased. The overallsize of the DC-DC converter can be reduced. Switches can switch fewernumbers of times. The life expectancies of the switches can be extended.The life expectancies of the inductors can be improved. Fewer and/orsmaller number of output capacitors can be used. There can be a fastertransient response. There can be a lower fluctuation in output voltagewhen current demand changes. The DC-DC converter can operate at higherfrequencies and/or use smaller inductors (e.g., in accordance with Eq.2). The size of the DC-DC converter can be reduced. Each pair ofswitches can operate at a maximum frequency that is efficient, yet theoverall frequency can be greater than the individual frequency of anypair of switches.

In some embodiments, power losses can be reduced. Using the equationP=I²*R, it can be seen that power loss increases with DC current (I).However, by splitting the current among multiple inductors, the overallpower loss can be reduced. Furthermore, the resistance of each inductoralso decreases. For example, by dividing the current (I_(o)) among twoinductors, P=2*[(I_(o)/2)²*R/2]=[I_(o) ²*R]/2, it can be seen that powerloss can be reduced by half. Accordingly, the distributed power deliveryamong multiple inductors provides improved efficiency. As demand forhigh current density DC-DC converters increases, multi-inductor, chipembedded DC-DC converters can provide small sizes and high currentdensities with less power loss.

In some embodiments, the smaller inductors in a multi-inductor, chipembedded DC-DC converter allows for faster transient responses tochanges in the demanded current. For example, as shown in FIG. 8B, achip embedded DC-DC converter may provide DC power to a CPU. The CPU maysuddenly experience a heavy computational load (e.g., utilize all coresand/or boosting its switching frequency), causing a sudden increase inthe power drawn (e.g., scaling from 1 amp to 10 amps in the ns range).As energy is drawn from an output capacitor (e.g., output capacitor 111of FIG. 1, FIG. 2), the voltage across the output capacitor may fall toofast beyond the DC power specifications (e.g., <1% drop in voltage)required by the CPU, risking stop errors. Accordingly, a feedback system(e.g., as shown in FIG. 14, FIG. 16, and FIG. 17) may be implemented toincrease the power delivered through the inductor to the capacitor andprevent the voltage drop. However, a high inductance resists the changein power delivery. Because a multi-inductor system uses smallerinductors, the transient feedback response of a multi-inductor, chipembedded DC-DC converter can be faster than the transient feedbackresponse of a DC-DC converter with fewer, larger inductors, and theresponse can have a lower output voltage drop. The DC-DC convertersdisclosed herein that have higher switching frequencies can utilizesmaller inductors, so that the single-inductor embodiments describedherein can have improved response to transient loads.

Example Dual Buck Converters

FIG. 10 shows an example dual inductor design for a dual buck converter1000 using a chip embedded DC-DC converter. A dual buck converter canuse two parallel inductors instead of using a single inductor.

FIG. 10 includes a first inductor 1001, a second inductor 1003, and aPCB 1005 that includes a chip embedded IC and other components (shown inFIGS. 11A, 11B, 11C and 11D, not visible in FIG. 10). A first input node1007A to the first inductor 1001 can correspond to a first pad 1007B onthe PCB 1005. A second input node 1009A to the second inductor 1003corresponds to a second pad 1009B on the PCB 1005. A voltage output nodecan 1011A correspond to a voltage output pad 1011B on the PCB 1005. Agraph 1013 shows the waveforms for Signal 1, Signal 2, and the OutputSignal.

The dual buck converter can be configured to include two inductors 1001,1003. The two inductors 1001, 1003 can be surface mounted on the PCB1005. In various embodiments, the two inductors 1001, 1003 can be twoseparate inductors positioned side by side, two separate inductorsvertically stacked on top of the other, or it a single magnetic corewith two inductor windings.

Signal 1 is provided to the first input node 1007A. Signal 1 has aperiod of T. Signal 2 is provided to the second input node 1009A. Signal2 also has a period of T. Signals 1 and 2 are out of phase with eachother and have an “on” time that is less than 50% of the period T. AnOutput Signal is formed by the combination of Signal 1 and Signal 2. Foreach pulse, the output signal has the same “on” time as Signal 1 andSignal 2. The “on” times of Signal 1 and Signal 2 are the same, and theeffective period of the Output Signal is reduced by half (the frequencyis doubled).

FIG. 12 shows an example circuit level schematic 1200 of a dual buckconverter including a chip embedded DC-DC converter. The schematicincludes a voltage source 1201, a first switch 1203 of a first switchpair, a second switch 1205 of the first switch pair, a third switch 1207of a second switch pair, a fourth switch 1209 of the second switch pair,a first inductor 1211, a second inductor 1213, an output capacitor 1217,and a voltage output node 1219.

The pair 1215 of inductors 1211, 1213 can be coupled outside of the PCB.The switches 1203, 1205, 1207, 1209 can be embedded in the PCB, eitheras standalone chips or as part of an IC chip that includes othercomponents (e.g., a driver, PWM controller, other switches). Thecapacitor 1217 can be coupled outside of the PCB or inside of the PCB.The inductors 1211 and 1213 can use a shared common core, or can useseparate cores.

The voltage source 1201 can be coupled to a drain of the first switch1203. The source of the first switch 1203 can be coupled to a first nodeof the first inductor 1211. The source of the first switch 1203 can alsobe coupled to a drain of the second switch 1205. The gates of the firstswitch 1203 and the second switch 1205 can be coupled to a driver (notshown in FIG. 12). The driver can drive opposite control signals to thefirst switch 1203 and the second switch 1205, turning the first switch1203 and the second switch 1205 on and off in alternation, such that oneof the first switch 1203 and the second switch 1205 is on while theother one is off. While the first switch 1203 is on and the secondswitch 1205 is off, energy can be provided from the voltage source 1201to the inductor 1211 and/or capacitor 1217, where the energy can bestored, causing the output voltage to rise. While the first switch 1203is off and the second switch 1205 is on, energy can be drained from theinductor 1211 and/or capacitor 1217, causing the output voltage to fall.

The voltage source 1201 can be coupled to a drain of the third switch1207. The source of the third switch 1207 can be coupled to a first nodeof the second inductor 1213. The source of the third switch 1207 canalso be coupled to a drain of the fourth switch 1209. The gates of thethird switch 1207 and the fourth switch 1209 can be coupled to a driver(not shown in FIG. 12). Accordingly, the driver can drive oppositecontrol signals to the third switch 1207 and the fourth switch 1209,turning the third switch 1207 and the fourth switch 1209 on and off inalternation, such that one of the third switch 1207 and the fourthswitch 1209 is on while the other one is off. While the third switch1207 is on and the fourth switch 1209 is off, energy can be providedfrom the voltage source 1201 to the inductor 1213 and/or capacitor 1217where the energy can be stored, causing the output voltage to rise.While the third switch 1207 is off and the fourth switch 1209 is on,energy can be drained from the inductor 1213 and/or the capacitor 1217,causing the output voltage to fall.

The second node of the first inductor 1211 and the second node of thesecond inductor 1213 can be coupled to the output node 1219 and alsocoupled to the output capacitor 1217, also referred to as a smoothingcapacitor. The voltage at the output node 1219 can be affected by theenergy stored in the capacitor 1217. The energy stored in the capacitor1217 can increase when current flows from the capacitor 1217 from eitherthe second node of either the first inductor 1211 or the second node ofthe second inductor 1213. Accordingly, a small signal ripple is providedto the capacitor as the switches provide or discharge energy.

The first pair of switches 1203, 1205 can be driven out of phase fromthe second pair of switches 1207, 1209. The first pair of switches 1203,1205 can also be driven at the same frequency and with the same periodas the second pair of switches 1207, 1209. Accordingly, in someembodiments, at most one of the upper switches 1203, 1207 will be on ata given time. The four switches 1203, 1205, 1207, 1209 can be drivenwith four respective signals that are all out of phase with each other.The first pair of switches 1203, 1205 and the first inductor 1211provide DC bucking functionality in parallel with the second pair ofswitches 1207, 1209 and the second inductor 1213.

FIG. 13A shows an example circuit level schematic 1300 of a DC-DCconverter including a chip embedded DC-DC converter. The components ofFIG. 13A can be the same as or similar to those in FIG. 12. The DC-DCconverter of FIG. 13A can include an additional capacitor 1221. Thecapacitor 1221 can store energy when switch 1203 is turned on. In someembodiments, energy can be stored such that the capacitor 1221 chargesto about half the voltage of the voltage supply 1201. When switch 1203is turned on, switch 1207 is turned off, and switch 1205 is turned off,transient current can flow through the capacitor 1221 to inductor 1211.When switch 1207 is turned on and switch 1209 is turned off, thecapacitor 1221 can provide power to switch 1207 and cause current toflow to inductor 1213. Capacitor 1221 also acts as an AC couplingcapacitor between switch 1207 and switch 1205. The components in FIG. 13are also arranged with a modified layout compared to those in FIG. 12,however, the DC-DC converters in FIG. 12 and FIG. 13A can functionsimilarly. The inductors 1211 and 1213 can use a shared common core, orcan use separate cores.

FIG. 13B shows an example circuit level schematic 1350 of a DC-DCconverter including a chip embedded DC-DC converter. The components ofFIG. 13 can be the same as or similar to those in FIG. 12. The firstpair of switches 1203, 1205 and first inductor 1211 can be coupled to afirst capacitor 1217A and configured to provide a first output voltageat a first output node 1219A. The second pair of switches 1207, 1209 andsecond inductor 1213 can be coupled to a second capacitor 1217B andconfigured to provide a second output voltage at a second output node1219B. The output voltages at the first and second output nodes 1219A,1219B can be the same voltage or can be different voltages. In someembodiments, a driver (e.g., as shown in FIG. 1, not shown in FIG. 13B)can separately drive the first pair of switches 1203, 1205 and secondpair of switches 1207, 1209 such that different voltages are provided atthe different nodes 1219A, 1219B. The inductors 1211 and 1213 can use ashared common core, or can use separate cores.

The embodiments shown in FIGS. 13A and 13B can be implemented on one ora plurality of IC dies. For example, in FIG. 13A, the switches 1203,1205, 1207, 1209 can all be included in a single IC (e.g., a monolithiceGaN IC). In some embodiments, the switches 1203, 1205, 1207, 1209 canbe divided among two or more separate devices. The embodiments shown inFIGS. 13A and 31B can also be controlled by one or more drivers and/orPWM controllers. For example, a first PWM controller can be coupled to afirst driver that drives a first pair of the switches from amongswitches 1203, 1205, 1207, 1209, and a second PWM controller can becoupled to a second driver that drives a second pair of switches fromamong switches 1203, 1205, 1207, 1209.

Example Designs for Chips Embedded in Dual Buck Converters

FIG. 11A shows a first example layout design 1100 for the embedded chipin a dual buck converter. The design includes an IC section 1101, afirst power switch 1103 of a first switch pair, a second power switch1105 of the first switch pair, a third power switch 1107 of a secondswitch pair, and a fourth power switch 1109 of the second switch pair.

In the embodiment of FIG. 11A, the IC section 1101, the first powerswitch 1103, the second power switch 1105, the third power switch 1107,and the fourth power switch 1109 are all included in the same IC chip.The IC section 1101 can include a PWM controller and a driver. Thedriver can be configured to drive the first switch pair out of phasewith the second switch pair. The driver can be configured to drive thefirst switch pair and the second switch pair with the same period andthe same frequency. The driver can also be configured to drive theswitches in each switch pair in alternation. In some embodiments, the ICsection 1101 includes a first driver configured to drive the firstswitch pair and a second driver configured to drive the second switchpair. The PWM controller can provide first PWM signals to the firstdriver and second PWM signals to the second drivers, and the first andsecond PWM signals can be out of phase with each other.

FIG. 11B shows a second example layout design 1120 for embedded chips ina dual buck converter. The design includes an IC chip 1121, a firstpower switch 1123 of a first switch pair, a second power switch 1125 ofthe first switch pair, a third power switch 1127 of a second switchpair, and a fourth power switch 1129 of the second switch pair.

The first power switch 1123 and the second power switch 1125 can be partof a first monolithic switch chip, such as a monolithic eGaN switchchip. The third power switch 1127 and the fourth power switch 1129 canpart of a second monolithic switch chip. In some embodiments, the firstmonolithic switch pair and the second monolithic switch pair can be partof the same monolithic chip. In some embodiments, the first monolithicswitch pair and the second monolithic switch pair can be separatemonolithic chips. The IC chip 1121 and the separate monolithic chips canbe embedded in a PCB. The IC section 1121 can include a PWM controllerand a driver. The driver can be configured to drive the first monolithicswitch pair out of phase with the second monolithic switch pair. Thedriver can be configured to drive the first monolithic switch pair andthe second monolithic switch pair with the same period and the samefrequency. The driver can also be configured to drive the switches ineach monolithic switch pair in alternation. In some embodiments, the ICsection 1121 includes a first driver configured to drive the firstmonolithic switch pair and a second driver configured to drive thesecond monolithic switch pair. The PWM controller can provide first PWMsignals to the first driver and second PWM signals to the seconddrivers, and the first and second PWM signals are out of phase with eachother.

FIG. 11C shows a third example layout design 1140 for embedded chips ina dual buck converter. The design includes an IC chip section 1141, afirst power switch 1143 of a first switch pair, a second power switch1145 of the first switch pair, a third power switch 1147 of a secondswitch pair, and a fourth power switch 1149 of the second switch pair.

The IC chip section 1141, the first power switch 1143 and the thirdpower switch 1147 can be part of a first IC chip. The second powerswitch 1145 and the fourth power switch 1149 can be separate chips, suchas separate monolithic eGaN chips, from the first IC chip. In someembodiments, the second power switch 1145 and the fourth power switch1149 can be part of the same monolithic chip. One, some, or all of thechips can be embedded in the PCB. The IC section 1141 can include a PWMcontroller and a driver. The driver can be configured to drive the firstswitch pair out of phase with the second switch pair. The driver can beconfigured to drive the first switch pair and the second switch pairwith the same period and the same frequency. The driver can also beconfigured to drive the switches in each switch pair in alternation. Insome embodiments, the IC section 1141 includes a first driver configuredto drive the first switch pair and a second driver configured to drivethe second switch pair. The PWM controller can provide first PWM signalsto the first driver and second PWM signals to the second drivers, andthe first and second PWM signals are out of phase with each other.

FIG. 11D shows a fourth example layout design 1160 for embedded chips ina dual buck converter. The design includes an IC chip section 1161, afirst power switch 1163 of a first switch pair, a second power switch1165 of the first switch pair, a third power switch 1167 of a secondswitch pair, and a fourth power switch 1169 of the second switch pair.

The IC chip section 1161, the first power switch 1163, the second powerswitch 1165, the third power switch 1167, and the fourth power switch1169 can be parts of separate IC chips. One, some, or all of theseparate IC chips can be embedded in a PCB. The IC section 1161 caninclude a PWM controller and a driver. The driver can be configured todrive the first switch pair out of phase with the second switch pair.The driver can be configured to drive the first switch pair and thesecond switch pair with the same period and the same frequency. Thedriver can also be configured to drive the switches in each switch pairin alternation. In some embodiments, the IC section 1161 includes afirst driver configured to drive the first switch pair and a seconddriver configured to drive the second switch pair. The PWM controllercan provide first PWM signals to the first driver and second PWM signalsto the second drivers, and the first and second PWM signals are out ofphase with each other.

Various additional arrangements are possible, such that any combinationof components 1161, 1163, 1165, 1167, and 1169 can be combined into anynumber of IC chips. In some embodiments, a multi inductor DC-DCconverter can be created by combining individual packages of individualor multi inductor DC-DC converters.

Additional Example Features of Multi-Inductor Chip Embedded DC-DCConverters

In some chip embedded DC-DC converters, the inductor is the largestphysical component. A multi-inductor chip embedded DC-DC converter caninstead use multiple, smaller inductors coupled in parallel. Switchescan be driven out of phase such that the multiple inductors charge anddischarge energy out of phase. In some embodiments, the outputs of themultiple inductors are coupled in parallel such that the output rippleof the multiple inductors is at a higher frequency than the outputripple of any individual inductor. In some embodiments, the outputs ofthe multiple inductors are coupled in parallel, and the output ripple ofthe multiple inductors has the same period as the output ripple of theindividual inductors.

The output ripple frequency of multiple inductor DC-DC converters can behigher, and the number and/or capacitance of the output capacitor(s) canbe reduced, and smaller output capacitor(s) can be used, in someembodiments.

As described above, the multiple inductor system can have a highereffective switching speed as compared with a single inductor system. Insome embodiments, this can be done without increasing the switchingspeed of the switches; instead, multiple switches can operate out ofphase with each other. Accordingly, a higher effective switching speedcan be reached without pushing individual switches to higher,inefficient switching speeds.

In accordance with Eq. 2, due to higher effective switching speed of themultiple inductors arranged in parallel, the inductance of the multipleinductors can be decreased. Accordingly, the inductors can be arrangedin parallel to lower the inductance, and/or smaller inductors withsmaller inductances can be used. Because smaller inductors can be used,the overall DC-DC converter size can be reduced, especially if theinductor(s) is (are) the largest component.

In some embodiments, further synergy can result from using smallerinductors: the switching speeds of the switches can increase because theinductance load of the switches is reduced. This can lead to fasterefficient switching speeds, further lowering the inductance according toEq. 2, and so on.

In some embodiments, a multi-inductor chip embedded DC-DC converter canuse a smaller output capacitor as compared to the output capacitor in asingle inductor DC-DC converter.

Examples of Chip Embedded DC-DC Converter with Feedback

FIG. 14 shows an example chip embedded DC-DC converter 1400 with anexternal ripple voltage feedback circuit. The chip embedded DC-DCconverter 1400 can include an embedded IC chip 1403 that can include adriver and/or modulator, as discussed herein. The IC chip can beembedded in a PCB 1401. The chip embedded DC-DC converter 1400 alsoincludes a first power switch 1405, a second power switch 1407, and aninductor 1409. The inductor 1409 is schematically represented to showits inductance component 1411 and its internal direct current resistance(DCR) component 1413.

The chip embedded DC-DC converter 1400 receives an input voltage at avoltage input node 1415 and provides an output voltage at an outputvoltage node 1417. An output capacitor 1421 is coupled to the outputnode 1417, and the output capacitor is schematically represented to showits capacitive component 1423 and its equivalent series resistance (ESR)1425. A feedback path 1427 is coupled from the output node to theembedded IC chip 1403.

The chip embedded DC-DC converter 1400 can receive the input voltage andcan generate the output voltage as previously described herein. Theoutput voltage can have small fluctuations, or ripples, as the switchesturn on and off. The ripple voltage (V_(ESR)) can be calculated bymultiplying the inductor current I_(L) by the ESR. The feedback path1427 senses the ripples and/or DC output voltage. A feedback indicationof the ripple and/or DC output voltage is provided to the embedded ICchip 1403. The modulator in the embedded IC chip 1403 can use thefeedback to control the switches 1405, 1407 to decrease the outputvoltage if the output voltage is too high, and to increase the outputvoltage if the output voltage is too low.

Feedback systems can use current mode control schemes and voltage modecontrol schemes to ensure DC-DC operational stability over a wide rangeof duty cycles. In current mode control schemes, a slope compensationscheme can be used and implemented with external components that may addto increased size and cost. Current mode control schemes may use type IIcompensation for loop stability and may have slower loop responses. Involtage mode control schemes, a voltage error can be amplified, fedback, and compensated for.

In some embodiments, the modulator can use a constant on time frequencymodulation scheme, a constant off time frequency modulation scheme, apulse width modulation scheme, or other scheme. Constant on time andconstant off time schemes can provide for stable DC-DC operation withhigh performance. In some embodiments, it can be desirable for themodulator to detect the ripple voltage to trigger certain controlevents. For example, in a constant on time scheme or constant off timescheme, the modulator can detect the AC ripple in order to generate anon or off pulse with a constant on or off time respectively, therebymodulating the frequency and affecting the periods of the controlsignals sent to switches 1405, 1407. For example, in a constant on timescheme, an on pulse of a fixed width can be provided to increase theoutput voltage in response to detecting a low output voltage incomparison to a reference voltage and/or in response to detecting asufficient amount of inductor current ripple. Accordingly, for aconstant on time scheme, each pulse has the same duration in the onstate, and the modulation is achieved by performing more or fewer pulsesper time (e.g., the off time between pulses would vary). A constant offtime scheme can be similar to the constant on time scheme describedherein, except that the off time between pulses is constant, and themodulation can be achieved by width of the on pulses. In another examplevoltage mode system, a frequency can be fixed, and the duty cycle of thepulse can be modulated. Variations can include leading or trail edgemodulation schemes. Any suitable modulation scheme can be used.Accordingly, the ESR 1425 can be designed and/or selected such that asufficiently large V_(ESR) can be detected by the modulator.

Some embodiments disclosed herein provide solutions to a number ofconflicting design challenges. Non-delayed feedback paths can providefast responses to changes in output voltage. Feedback paths can be usedin some modulation/control schemes, such as constant on time or constantoff time schemes, to control when the switches 1405, 1407 are turned onor off. To provide a measurably large V_(ESR) signal along the feedbackpath that is reliably detectable by the modulator, the ESR 1425 of thecapacitor 1421 can be designed and/or selected such that a sufficientlylarge ripple is caused. At the same time, it can be desirable tominimize the ripple voltage. A DC-DC converter can ideally generate apure DC voltage. In practice, many applications allow small ripples onthe output of a DC-DC converter but only within a small margin. Somedevices powered by a DC power supply may require a maximum of 3% ripple,2%, ripple 1% ripple, 0.5% ripple, 0.1% ripple, 0.05% ripple, 10 mVripple, 5 mV ripple, 3 mV ripple, 1 mV ripple, 0.5 mV ripple, a smalleramount of ripple, or an undetectably low amount of ripple, or any rangesbounded by any of these values, although in some instances valuesoutside these ranges can be used. For example, some point of loaddevices may specify that a DC power supply provide a 1.00 V DC outputwith no more than 1% (10 mV) ripple or variation from the 1.00 V value.A very low ESR capacitor can be used to achieve low ripple output.However, if the ripple is too low, then the modulator might not workbased on the ripple feedback (e.g., the modulator might not distinguishripple from noise, might operate erratically, etc.).

The disclosure herein includes some embodiments of DC-DC converters thatuse a ripple-triggered modulator, low ESR capacitors, and provide alow-ripple DC output.

Example Current and Ripple Graphs

FIG. 15 shows example graphs 1500, 1550 of inductor current I_(L) overtime and equivalent series resistance voltage V_(ESR) (also referred toas ripple voltage) over time. The line 1501 indicates current I_(L)through the inductor 1409 of FIG. 14. The line 1551 indicates the outputripple voltage V_(ESR) at node 1417 of FIG. 14.

The inductor current I_(L) increases when switch 1405 is turned on andswitch 1407 is turned off. I_(L) increases according to the equation:

$\begin{matrix}{I_{Lon} = {{\frac{V_{in} - V_{out}}{L}*T_{on}} + I_{o}}} & {{{Eq}.\mspace{14mu} 3}A}\end{matrix}$

where V_(in) is the input voltage, V_(out) is the output voltage, L isthe inductance, T_(on) is the amount time that switch 1405 is turned on,and I_(o) is an initial current.

The inductor current I_(L) decreases when switch 1405 is turned off andswitch 1407 is turned on. I_(L) decreases according to the equation:

$\begin{matrix}{I_{Loff} = {{\frac{- V_{out}}{L}*T_{off}} + I_{o}}} & {{{Eq}.\mspace{14mu} 4}A}\end{matrix}$

where V_(out) is the output voltage, L is the inductance, T_(off) is theamount time that switch 1405 is turned off, and I_(o) is an initialcurrent. Equations 3 and 4 are the applied version of the generalequation, V=L(dI/dt), where V is the voltage across an inductor, dI/dtis the rate of change in current with respect to time.

Based on equations 3 A and 4 A, the rates of change in the current canbe determined by time derivatives such that:

$\begin{matrix}{{\frac{d}{dt}I_{Lon}} = \frac{V_{in} - V_{out}}{L}} & {{{Eq}.\mspace{14mu} 3}B} \\{{\frac{d}{dt}I_{Loff}} = \frac{- V_{out}}{L}} & {{{Eq}.\mspace{14mu} 4}B}\end{matrix}$

V_(ESR) fluctuates up and down with the inductor current IL. However,V_(ESR) and I_(L) increase and decrease with different slew rates (e.g.,with different slopes). The difference in rates is affected by the ESRof the capacitor 1421. The voltage can be determined by multiplying theinductor current I_(L) by the ESR according to the equation V=I*R_(ESR).Accordingly,

$\begin{matrix}{{\frac{d}{dt}V_{on}} = {\frac{V_{in} - V_{out}}{L}*R_{ESR}}} & {{{Eq}.\mspace{14mu} 3}C} \\{{\frac{d}{dt}V_{off}} = {\frac{- V_{out}}{L}*R_{ESR}}} & {{{Eq}.\mspace{14mu} 4}C}\end{matrix}$

As shown in the graphs 1500, 1550, as the current I_(L) increases anddecreases, the V_(ESR) also increases and decreases at the same time,but at different slew rates (different slopes). The slew rate of V_(ESR)is proportional to and affected by the ESR according to the equationV_(ESR)=IL*ESR. Accordingly, for low ESR values, the V_(ESR) may have asmall amplitude, even if I_(L) is large. For example, the inductorcurrent I_(L) is 3.0 A with a 50% ripple so that it fluctuates from 1.5A to 4.5 A with an amplitude of 3.0 A. If a low ESR is 1 mΩ, then theV_(ESR) may fluctuate between −1.5 mV to 1.5 mV, which can be too smalland/or difficult for some modulators to reliably use. Also, the V_(ESR)alternates between positive and negative values while the currentremains positive.

Example Low ESR, Low Ripple, Chip Embedded DC-DC Converters

FIG. 16 shows an example chip embedded DC-DC converter with an externalripple voltage feedback circuit 1600. The embodiment of FIG. 16 caninclude a PCB 1601, driver 1603, first power switch 1605 (such as aneGaN switch), a second power switch 1607 (such as an eGaN switch), aninductor 1609, output capacitor 1621, and output node 1617. FIG. 16 alsoincludes a resistor 1643, capacitor 1645, AC bypass capacitor 1647, afeedback path 1627, a comparator 1629, AND gate 1631, one-shot circuit1633, inverter 1635, minimum time delay counter 1637, resistor 1639, andresistor 1641.

The output capacitor 1621 can be one or more low ESR capacitors. The lowESR effect can also be achieved by coupling a plurality of capacitors inparallel such that the effective parallel ESR is reduced. For example,each capacitor may have an ESR in the mΩ range (e.g., 1 mΩ, 10 mΩ, 100mΩ) or lower in the μΩ range (e.g. 10μΩ, 100μΩ), and the arrangement ofthe capacitors in parallel may reduce the effective parallel ESR evenfurther. As a result of the low ESR, the ripple voltage at node 1617might be too small to reliably use for feedback, but a low ripple DCoutput is provided at node 1617. For example, a 1.5 A ripple through theinductor may cause only a 1.5 mV ripple when a 1 mΩ ESR capacitor isused. The one or more output capacitors 1621 can have a total ESR of1000 mΩ, 100 mΩ, 10 mΩ, 1 mΩ, 100μΩ any values therebetween, any rangesbounded by any of these values, or a smaller ESR, although in someinstances values outside these ranges can be used. In some embodiments,the output voltage of the DC-DC converter can have an AC voltage rippleof 3% or less, 2%, or less, 1% or less, 0.5% or less, 0.1% or less,0.05% or less, 10 mV or less, 5 mV or less, 3 mV or less, 1 mV or less,0.5 mV or less, a smaller amount of ripple, a ripple that cannot bereliable detected, an undetectably low amount of ripple, or any rangesbounded by any of these values, although in some instances valuesoutside these ranges can be used. The low ESR and low ripple valuesdiscussed herein can relate to other embodiments, as well, such as tothe embodiment of FIG. 17.

In order to sense the ripple and provide a feedback voltage, theresistor 1643 can be coupled in series with the capacitor 1645, and theseries combination of the resistor 1643 and the capacitor 1645 can becoupled in parallel across the inductor 1609. The capacitor 1645 blocksDC signals. AC signals, such as ripples, can still be sensed. Thecapacitor 1645 and the resistor 1643 form a voltage divider for ACsignals, and the sensed ripple can pass through AC bypass capacitor 1647to the feedback path 1627. The values of the resistor 1643 and capacitor1645 can be set such that equation 5 is satisfied:

$\begin{matrix}{\frac{L}{{DCR}_{L}} = {{Rx}*{Cx}}} & {{Eq}.\mspace{14mu} 5}\end{matrix}$

where L is the value of the inductance of inductor 1609, DCR_(L) is thedirect current resistance (“DCR”) of the inductor 1609, Rx is theresistance of the resistor 1643, and Cx is the capacitance of thecapacitor 1645. Accordingly, a circuit can be provided to measurably andreliably sense the inductor current ripple independently of the ESRvalue.

Resistors 1639 and 1641 can form a voltage divider coupled to the outputnode 1617. The voltage divider can divide the voltage output at theoutput node 1617. In some implementations, the ripple at the output node1617 can be small, difficult to detect, within a noise threshold, orotherwise unreliable for modulation purposes due to the low ESR ofoutput capacitor 1621. Accordingly, the voltage divider can primarilyact as a DC voltage divider.

The feedback path 1627 is coupled to the voltage divider to receive a DCvoltage and is also coupled to the AC bypass capacitor 1647 to sense theripple voltage. The feedback path is also coupled to a comparator 1629and compared to a reference voltage. The reference voltage can beprovided by a reference voltage generator (not shown), such as a bandgapgenerator, crystal, digital to analog converter (“DAC”), battery, etc.In some embodiments, a DAC is used to provide the reference voltage, anda digital signal can be provided to the DAC to set a desired referencevoltage.

The comparator 1629 can generate a comparator output signal based on acomparison of the feedback signal and the reference voltage. For anexample constant on time modulator, the comparator 1629 may generate ahigh output signal when the feedback signal falls below the referencevoltage.

The output of the comparator 1629 can be provided to a one-shot circuit1633 that generates a constant on time PWM signal, which can be providedto the driver 1603. The output of the one-shot circuit 1633 can also beprovided to an inverter 1635, a minimum off time delay circuit 1637, andan AND gate 1631 to prevent the PWM signal from remaining high.

The configuration of the resistor 1643, capacitor 1645, and AC bypasscapacitor 1647 can cause a significant, measurable ripple to be detectedand injected to the feedback path 1627 despite the low ESR capacitor1621 and despite the low output ripple. Accordingly, the detected ripplecan be larger than the output ripple. The AC ripple injected to thefeedback path 1627 can be expressed by:

$\begin{matrix}{V_{cx} = \frac{I_{L}*L}{( {R_{x}*C_{x}} )}} & {{Eq}.\mspace{14mu} 6}\end{matrix}$

where V_(cx) is the ripple voltage on capacitor 1645, I_(L) is theinductor peak to peak current ripple, R_(x) is the resistance ofresistor 1643, and C_(x) is the capacitance of capacitor 1645.

In some embodiments, the PCB 1601 and its internal components can bepackaged, and users can provide and/or configure the circuit includingthe inductor 1609, resistor 1643, capacitor 1645, capacitor 1621,capacitor 1645, AC bypass capacitor 1647, resistor 1639, and resistor1641. In such embodiments, the values of the inductor 1609, resistor1643, and/or capacitor may be selected and tuned according to equation6. For example, if the inductor 1609 is changed for an application(e.g., to have a different inductance and/or DCR), a user can solve Eq.6 and then select, source, and change the resistor 1643 and/or capacitor1645 to correspond to the new L and DCR_(L) values of the inductor 1609.

In some embodiments, some or all components shown in FIG. 16 can beincluded in a single package. In some embodiments, including some butnot all of the resistor 1643, capacitor 1645, and inductor 1609 in apackage can limit the ability to tune the circuit according to equation6. For example, if the resistor 1643 and capacitor 1645 are included inthe package but the inductor 1609 is selected by an end user, then theend user can be restricted to using particular inductors with particularL and DCR_(L) values in order to satisfy equation 6. In such a systemand in any improperly tuned system, an improperly selected inductor 1609can cause system instability and/or malfunction, which may damagecomponents receiving power from the DC-DC converter. In some instances,it can be desirable for the DC-DC converter to be properly tuned andprovided as a single packaged device that does not require end usermodification. Some embodiments disclosed herein can include the inductor1609, the resistor 1643, and the capacitor 1645 as an single package.

Example Low ESR, Low Ripple, DC-DC Converters

FIG. 17 shows an example DC-DC converter 1700 (which can be achip-embedded DC-DC converter, in some embodiments) with an internalripple voltage feedback circuit. The chip embedded DC-DC converter 1700includes a package 1701, a driver 1703, a first power switch 1705, asecond power switch 1707, and an inductor 1709, which can be similar toother embodiments described herein. The DC-DC converter 1700 can receivean input voltage at a voltage input node 1715 and can provide an outputvoltage at an output voltage node 1717. An output capacitor 1721 (e.g.,a low ESR output capacitor or a plurality of parallel capacitors with alow parallel ESR) can be coupled to the output node 1717. A feedbackpath 1727 can be coupled from the output node to a comparator 1729. Thecomparator output can be coupled to an AND gate 1731 and a one-shotcircuit 1733 to provide a PWM signal to the driver 1703. A rampgenerator 1751 can emulate an inductor ripple current (e.g., emulatesthe current 1501 in FIG. 15) and outputs a voltage representation of theripple current (e.g., 1551 in FIG. 15). In some embodiments, the outputof the ramp generator 1751 can be combined (e.g., added or subtracted)with a reference voltage at a signal combiner 1753. In some embodiments,the inductor ripple signal output by the ramp generator can be added tothe feedback signal instead of being subtracted from the referencevoltage. The comparator 1729 can perform a comparison involving theripple signal output by the ramp generator 1751 and a reference voltage.The result of the comparison can be used in the feedback loop fordriving the system (e.g., the switches 1705 and/or 1707).

The inductor 1709 can be included in the chip embedded DC-DC converterpackage, such as shown in FIG. 1, FIG. 3, FIG. 4A, and FIG. 4B. A lowESR output capacitor 1721 can be coupled to the output node 1717. The atleast one output capacitor 1721 can have a low ESR (e.g., similar to thevalues and ranges discussed herein with regards to the embodiment ofFIG. 16). For example, the ESR can be in the mΩ range (e.g., 1 mΩ, 10mΩ, 100 mΩ) or lower in the μΩ range (e.g. 10μΩ, 100μΩ), and thearrangement of the capacitors in parallel may reduce the effectiveparallel ESR even further. The output voltage can have a low or no ACripple (e.g., similar to the values and ranges discussed herein withregards to FIG. 16) such that the DC-DC converter can meet low rippleoutput specifications as required by some devices. However, the same lowAC ripple may be small, difficult to detect, within a noise threshold,nonexistent, or otherwise unreliable for modulation purposes (e.g., dueto the low ESR of output capacitor 1721), and it can be difficult to usethat AC ripple for modulation purposes. The DC output voltage isprovided via feedback path 1727 on the feedback path 1727 (e.g., alongwith any small (but not reliably measurable) AC ripple or no AC rippleat all).

A ramp generator 1751 emulates the inductor ripple independently of thecapacitor 1721 and/or its ESR. An example ramp generator is describedbelow with respect to FIG. 18. Inputs to the ramp generator can includethe input voltage, the output voltage, a switch signal, and the inductorvalue. The output of the ramp generator 1751 can be combined with areference voltage for comparison to the voltage on the feedback path1727, or the output of the ramp generator 1751 can be combined with thevoltage on the feedback path 1727 for comparison to a reference voltage.The voltage reference can be provided, for example, by a DAC. The DACcan generate a voltage output based on a digital input. Accordingly, theDAC voltage can be adjusted in small increments. For example, a 9 bitDAC may have adjustable output voltages in increments of 5 mV. The DACcan be used to set and/or tune an output voltage for the DC-DCconverter. Other examples of voltage references include crystals,bandgap references, batteries, etc., any of which may be unable. Thereference voltage combined with the emulated inductor ripple can beprovided to an input of the comparator 1729, as shown in FIG. 17.

The ramp generator 1751 can be included in the package. The rampgenerator 1751 can be included in a chip embedded IC, along with thedriver 1703 and other components. The inductor can also be includedwithin the package. The ramp generator 1751 can be tuned and configuredfor the particular inductor 1709 that is selected within the packagebefore the package is provided to a user. In contrast to designsallowing user selectable inductors with different properties, a designerwho selects the packaged inductor 1709 can know the inductor value andcharacteristics, allowing the designer to extract and/or determine theslew rate of the inductor 1709 and replicate the slew rate using theramp generator 1751. In some embodiments, instead of using the actualripple signal (e.g., at the inductor) in the feedback loop, the systemcan use the ramp generator to emulate the ripple signal (e.g., that ispresent at the inductor). The ramp generator 1751 can determine anemulated ripple signal based on the values of the input voltage V_(in),V_(out), the inductance values of the inductor L (which can be a knownvalue when the inductor is integrated into the DC-DC converter package),and a switching signal SW. The switching signal can be indicative of thestate of one or both of the switches 1705, 1707 and/or the time that oneof both of the switches 1705, 1707 changed states (e.g., the HS and LSsignals). Since the ramp generator knows the inductance, the input andoutput voltages, and the timing of the switches, it is able to determinea simulated ripple signal that emulates the actual ripple signal in thecircuit (e.g., the ripple at the inductor). The emulated ripple can beproportional to the ripple in the inductor. The emulated ripple canchange with the same slope (e.g., at the same rate) that the ripple inthe inductor changes. The emulated ripple in a system with a low ESRcapacitor 1721 can emulate a ripple that would be seen at node 1417 ofFIG. 14 when a low ESR capacitor 1421 is not used.

The inductor ripple signal can be generated to accurately reflect theripple through inductor 1709. By using a ramp generator to generate theinductor ripple signal, a minimum capacitor ESR is unnecessary forsensing/detecting the AC ripple. Accordingly, the output voltage can bea cleaner DC signal with a smaller or no AC ripple.

In some embodiments, a comparator compares the output of the DC-DCconverter to the combination of the reference signal with the emulatedinductor ripple. For example, in a constant on time modulation scheme,the comparator can output a high signal when the output signal on thefeedback path 1727 falls below the value of the reference voltagecombined with the emulated inductor ripple. The high signal can beprovided through an AND gate to a one-shot circuit, which provides aconstant on time PWM pulse to the driver 1703, which drives switch 1705on and switch 1707 off. An inverter 1735 and minimum off time delaycircuit 1737 coupled to the AND gate can prevent the one-shot circuit1733 from triggering too frequently by ensuring that switch 1705periodically turns off and switch 1707 periodically turns on. Variousother implementations can be used to drive the switches based on theoutput of the comparator 1729.

Although the operation of the circuits in FIG. 16 and FIG. 17 aredescribed with respect to a constant on time modulation scheme, it isunderstood that the teachings and disclosures herein can apply to anyvoltage mode modulation scheme, such as a constant off time scheme withthe appropriate modifications to the circuitry (e.g., minimum off timedelay changed to minimum on time delay, some comparisons and/or signalscan be inverted, etc.). Furthermore, the teachings and disclosure hereincan further be applied to current mode modulation schemes or voltagemodulation schemes.

FIG. 18 shows an example circuit level schematic of a ramp generator1800. The ramp generator 1800 can include a first current source 1801, asecond current source 1803, a capacitor 1805, a ramp voltage output node1807, a first switch 1809, a second switch 1811, a trim controller 1813,and resistors 1815A, 1815B. The trim controller 1813 and/or the currentsources 1801, 1803 can be coupled to the I²C and/or PMBUS to receivetrim and/or adjustment commands.

The ramp generator can be configured to generate an output according tothe following equations:

$\begin{matrix}{V_{{ramp} - {ON}} = {{\frac{k}{C_{ramp}}( {V_{in} - V_{out}} )*t_{on}} + V_{o}}} & {{{Eq}.\mspace{14mu} 7}A} \\{V_{{ramp} - {{OF}F}} = {{\frac{k}{C_{ramp}}( {- V_{out}} )*t_{off}} + V_{o}}} & {{{Eq}.\mspace{14mu} 8}A}\end{matrix}$

where V_(ramp-ON) and V_(ramp-OFF) are the respective on and offvoltages (output as the inductor ripple output of the ramp generator1751 in FIG. 17), k can be a constant fixed factor, V_(in) is the inputvoltage (e.g., the voltage provided at node 1715 in FIG. 17), V_(out) isthe output voltage (e.g., the voltage provided at node 1717 in FIG. 17),where k is a number measured in Amps per volts, C_(ramp) is acapacitance of the capacitor 1805, t_(on) is an amount of time that theDC-DC converter is providing power to the inductor (e.g., while switch1809 is closed and switch 1811 is open), t_(off) is an amount of timethat the DC-DC converter is not providing power to the inductor (e.g.,while switch 1809 is open and switch 1811 is closed), and V_(o) is astarting voltage. The ripple voltage slew rates (also known as “slopes,”measured in volts per second) are indicated by the coefficients that thetime periods (t_(on), t_(off)) are multiplied by:

$\begin{matrix}{{\frac{d}{dt}V_{{ramp} - {ON}}} = {\frac{k}{C_{ramp}}( {V_{in} - V_{out}} )}} & {{{Eq}.\mspace{14mu} 7}B} \\{{\frac{d}{dt}V_{{ramp} - {{OF}F}}} = {\frac{k}{C_{ramp}}( {- V_{out}} )}} & {{{Eq}.\mspace{14mu} 8}B}\end{matrix}$

Eq. 7 and Eq. 8 alone do not reveal how to set the value for k toemulate a voltage related to the inductor ripple, which should depend oninductance of inductor 1709. If the ramp generator is configured toemulate the slew rate in Eq. 3C, then Eq. 7B and Eq. 3C can be set equalto each other, where C_(ramp) is set equal to C_(x), and a resistorR_(eq) is selected to replace R_(ESR) such that:

$\begin{matrix}{{\frac{k}{C_{ramp}}( {V_{in} - V_{out}} )} = {\frac{V_{in} - V_{out}}{L}*R_{eq}}} & {{Eq}.\mspace{14mu} 9} \\{k = {\frac{C_{ramp}}{L}*R_{eq}}} & {{Eq}.\mspace{14mu} 10}\end{matrix}$

Accordingly, the value for k can be determined, and will be a constantnumber when the capacitance of capacitor 1805, the resistance ofresistors 1815A, 1815B, and the inductance of inductor 1709 are fixed.Furthermore, the relationship between k and inductance is revealed to bean inverse relationship. The constant value k can be determined if theinductance of inductor 1709 is known. Accordingly, the inductance ofinductor 1709 can be measured, and the ramp generator can be trimmedand/or configured.

The first current source 1801 can be a voltage controlled current source1801. The output of the voltage controlled current source 1801 can becontrolled, at least in part, by the V_(in) voltage and by k. In someembodiments, the output of the voltage controlled current source can becontrolled by the V_(in) voltage multiplied by k. Accordingly, as Lincreases, k decreases, and current source 1801 can be trimmed todecrease the output current, and as L decreases, the current source 1801can be trimmed to increase the output current. The current source 1801is coupled to the first switch 1809 and to ground.

The second current source 1803 can be a voltage controlled currentsource 1803. The output of the voltage controlled current source 1803can be controlled, at least in part, by the V_(out) voltage and by k. Insome embodiments, the output of the voltage controlled current sourcecan be controlled by the V_(out) voltage multiplied by k. Accordingly,as L increases, k decreases, and the current source 1803 can be trimmedto decrease the output current, and as L decreases, the current source1803 can be trimmed to increase the output current. The current source1803 is coupled to the second switch 1811 and to ground.

A trim controller 1813 is coupled to the current sources 1801, 1803. Thetrim controller 1813 is configured to adjust and/or set the output ofthe current sources 1801, 1803 based, at least in part, on theinductance of inductor 1709 (including respective or effective parallelinductors in various multi-inductor configurations). In someembodiments, the trim controller 1813 can be configured to adjust and/orset the output of the current sources 1801, 1803 based, at least inpart, on the inductance of inductor 1709, the capacitance of capacitor1805, and/or the resistance of resistors 1815A, 1815B. In someembodiments, the value for C_(ramp)*R_(eq) can be set to a constantvalue, and the inductance of inductor 1709 is provided to the trimcontroller 1813.

A first switching signal (e.g., the same signal HS provided to switch1705 in FIG. 17) can be provided to the first switch 1809. A secondsignal (e.g., the same signal LS provided to switch 1707 in FIG. 17) canbe provided to the second switch 1811. The first and second switches1809, 1811 can be smaller switches than the power switches 1705, 1707 inFIG. 17.

A capacitor 1805 can have one end coupled between the first switch 1809and the second switch 1811. Another end of the capacitor 1805 can becoupled to ground.

When the first switch 1809 is closed and the second switch 1811 is open,the first current source 1801 is configured to generate a currentcontrolled by the voltage k*V_(in), charging capacitor 1805 such that avoltage at node 1807 is generated according to Eq. 7A and ramps up asdescribed by Eq. 7B.

When the first switch 1809 is open and the second switch 1811 is closed,the second current source 1803 is configured to generate a currentcontrolled by the voltage k*V_(out), sinking current from capacitor 1805such that the voltage at node 1807 is decreases according to Eq. 8A,creating a negative voltage ramp as described by Eq. 8B.

As the current is drained from the capacitor 1805, the voltage acrossthe capacitor decreases. Accordingly, the ramp generator can emulate anemulated inductor ripple and provide a usable voltage signal that isindependent of the output capacitor and/or ESR.

The increasing and decreasing voltage output by the ramp generator atnode 1807 can therefore emulate, be the same as, and/or be proportionalto a ripple through the inductor 1709, even when a low ESR capacitor1721 is used such that a voltage ripple cannot be reliably measureddirectly from the low ESR capacitor. By providing the inductor 1709,capacitor 1805, and resistors 1815A, 1815B, the values can bedetermined, and the DC-DC converter shown in FIG. 17 and FIG. 18 can beconfigured accordingly.

Unlike solutions that require users to configure external components,the packaged chip embedded DC-DC converter shown in FIG. 18 can includea self-contained, tuned feedback system. Accordingly, users do not needto engineer feedback systems, calculate proportions between inductances,DCR's, resistances, and capacitances. Furthermore, integrating thefeedback and/or modulation components into a package and/or one or moreIC within a package can save space in comparison to using externalfeedback components.

Example Method of Making and Using Low ESR, Low Ripple, Chip EmbeddedDC-DC Converters

FIG. 19 shows an example method of making and using a low ESR, lowripple, chip embedded DC-DC converter. The DC-DC can be configured toreceive power at an input node at a first input voltage and output powerat an output node at second output voltage that is different from thefirst input voltage.

At block 1901, an IC chip can be embedded in a PCB, as discussed herein.The IC chip can include some or all of: a driver, switches, rampgenerator, and modulator circuitry, for example, as shown in FIG. 1,FIG. 3, FIG. 14, FIG. 16, and FIG. 17. In some embodiments, a pluralityof IC chips can be embedded in the PCB, for example, as shown in FIG.11B through FIG. 11D.

At block 1903, one or more inductors can be coupled to the IC chip andto a feedback path, for example, as shown in FIG. 1, FIG. 3, FIG. 14,FIG. 16, and FIG. 17. The inductor(s) and feedback path can be coupledto the output node. In some embodiments, a plurality of inductors can becoupled in a multi-inductor arrangement, for example, as described withrespect to FIG. 10 through FIG. 13. The inductors can be configured toreceive power and be part of an LC circuit arrangement that storesenergy. The LC arrangement can include one or more capacitors, which canbe low ESR capacitors. A parallel arrangement of capacitors can providean effective low ESR. The second output voltage can form across thecapacitor(s). Block 1903 can include measuring the inductance of theinductor(s).

At block 1905, a ramp generator can be included. The ramp generator canbe included as part of the integrated circuit, as part of a differentintegrated circuit, included in the PCB, or otherwise included in theDC-DC converter package. An example ramp generator is described withrespect to FIG. 17 and FIG. 18. The ramp generator can include a firstcurrent source, a second current source, and a capacitor coupled betweenthe first and second current sources.

At block 1907, the ramp generator can be configured to emulate a ripplethrough the inductor. This can include trimming the first or secondcurrent sources based at least in part on a value of the inductor. Thevalue of the inductor can be measured in order to determine the valuefor trimming. The ripple can be generated independently of the outputcapacitor and/or the ESR of the output capacitor. The first inputvoltage, second output voltage, inductance of the inductor, and aswitching signal can be provided to the ramp generator. The currentsources can switch on and off based on the switching signal. Theswitching signal can be provided to and/or generated from one or morepower switches in the DC-DC converter.

At block 1909, a feedback signal, reference signal, and ripple voltagecan be provided for signal modulation. The feedback signal can be a DCoutput signal (e.g., with no or little AC ripple). The AC ripple on theDC output signal can be insufficient to reliably use for modulation, insome instances. The reference signal can be a desired DC output signalthat can be generated by a crystal, bandgap reference, DAC, battery,etc. The ripple voltage can be output by the ramp generator. Thefeedback signal, reference signal, and ripple voltage can be provided toa comparator.

At block 1911, one or more switches can be modulated and driven based atleast in part on the feedback signal, the reference signal, and theripple voltage. The modulation scheme can be, for example, a voltagemode modulation scheme such as a constant on time or constant off timescheme. The feedback signal can be compared to the reference signal. Theripple voltage can also be included in the comparison. The modulator cangenerate a control signal, such as a pulse, to drive one or moreswitches, based at least in part on the comparison.

At block 1913, a modulated output signal can be provided by the DC-DCconverter.

Additional Details

The principles and advantages described herein can be implemented invarious apparatuses. Also, chip embedded DC-DC converters can be used invarious apparatuses for improved performance, and chip embedded DC-DCconverters that perform at specifications and provided at lower costscan decrease the overall price of those various apparatuses. Examples ofsuch apparatuses can include, but are not limited to, consumerelectronic products, parts of the consumer electronic products,electronic test equipment, etc. Examples of parts of consumer electronicproducts can include clocking circuits, analog-to-digital converters,amplifiers, rectifiers, programmable filters, attenuators, variablefrequency circuits, etc. Examples of the electronic devices can alsoinclude memory chips, memory modules, circuits of optical networks orother communication networks, cellular communications infrastructuresuch as base stations, radar systems, and disk driver circuits. Consumerelectronic products can include, but are not limited to, wirelessdevices, a mobile phone (for example, a smart phone), a wearablecomputing device such as a smart watch or an ear piece, healthcaremonitoring devices, vehicular electronics systems, a telephone, atelevision, a computer monitor, a computer, a hand-held computer, atablet computer, a laptop computer, a personal digital assistant (PDA),a microwave, a refrigerator, a stereo system, a cassette recorder orplayer, a DVD player, a CD player, a digital video recorder (DVR), aVCR, an MP3 player, a radio, a camcorder, a camera, a digital camera, aportable memory chip, a washer, a dryer, a washer/dryer, a copier, afacsimile machine, a scanner, a multi-functional peripheral device, awrist watch, a clock, etc. Further, apparatuses can include unfinishedproducts.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,”“include,” “including,” and the like are to be construed in an inclusivesense, as opposed to an exclusive or exhaustive sense; that is to say,in the sense of “including, but not limited to.” The words “coupled” orconnected”, as generally used herein, refer to two or more elements thatcan be either directly connected, or connected by way of one or moreintermediate elements. Additionally, the words “herein,” “above,”“below,” and words of similar import, when used in this application,shall refer to this application as a whole and not to any particularportions of this application. Where the context permits, words in theDetailed Description using the singular or plural number can alsoinclude the plural or singular number, respectively. The words “or” inreference to a list of two or more items, is intended to cover all ofthe following interpretations of the word: any of the items in the list,all of the items in the list, and any combination of the items in thelist. The words “and/or” is also intended to cover all of the followinginterpretations of the word: any of the items in the list, all of theitems in the list, and any combination of the items in the list. Theterm “based on,” as generally used herein, encompasses the followinginterpretations of the term: solely based on or based at least partlyon. All numerical values provided herein are intended to include similarvalues within a measurement error.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states.

The various features and processes described above may be usedindependently of one another, or may be combined in various ways. Allpossible combinations and subcombinations are intended to fall withinthe scope of this disclosure. In addition, certain method or processblocks may be omitted in some implementations. The methods and processesdescribed herein are also not limited to any particular sequence, andthe blocks or states relating thereto can be performed in othersequences that are appropriate. For example, described blocks or statesmay be performed in an order other than that specifically disclosed, ormultiple blocks or states may be combined in a single block or state.The example blocks or states may be performed in serial, in parallel, orin some other manner. Blocks or states may be added to or removed fromthe disclosed example embodiments. The example systems and componentsdescribed herein may be configured differently than described. Forexample, elements may be added to, removed from, or rearranged comparedto the disclosed example embodiments.

The teachings of the embodiments provided herein can be applied to othersystems, not necessarily the systems described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel methods and systems describedherein can be embodied in a variety of other forms. Furthermore, variousomissions, substitutions and changes in the form of the methods andsystems described herein can be made without departing from the spiritof the disclosure. The accompanying claims and their equivalents areintended to cover such forms or modifications as would fall within thescope and spirit of the disclosure.

Other Embodiments

The following list has example embodiments that are within the scope ofthis disclosure. The example embodiments that are listed should in noway be interpreted as limiting the scope of the disclosure. Variousfeatures of the example embodiments that are listed can be removed,added, or combined to form additional embodiments, which are part ofthis disclosure:

1. A direct current to direct current (DC-DC) power converter,comprising:

-   -   a lower printed circuit board (PCB) part having a bottom side        and a top side;    -   an upper printed circuit board (PCB) part having a bottom side        and a top side;    -   embedded circuitry that is between the top side of the lower PCB        part and the bottom side of the upper PCB part, the embedded        circuitry comprising:        -   a pulse width modulator; and        -   at least one switch;    -   one or more vias extending through the upper PCB part;    -   an inductor positioned over the top side of the upper PCB part,        wherein the one or more vias are electrically coupled to the        inductor and to the embedded circuitry.

2. The DC-DC power converter of embodiment 1, wherein the embeddedcircuitry includes an integrated circuit (IC).

3. The DC-DC power converter of embodiment 2, wherein a footprint of theinductor at least partially overlaps a footprint of the integratedcircuit.

4. The DC-DC power converter of any one of embodiments 1 to 3, whereinno wire-bonds electrically interconnect the inductor and the embeddedcircuitry.

5. The DC-DC power converter of any one of embodiments 1 to 4, whereinthe circuitry has a switching rate of at least 1 MHz.

6. The DC-DC power converter of any one of embodiments 1 to 4, whereinthe circuitry has a switching rate of at least 3 MHz.

7. The DC-DC power converter of any one of embodiments 1 to 4, whereinthe circuitry has a switching rate of at least 5 MHz.

8. The DC-DC power converter of any one of embodiments 1 to 7, whereinthe circuitry has a switching rate of up to 7 MHz.

9. The DC-DC power converter of any one of embodiments 1 to 8, whereinthe at least one switch comprises an enhanced gallium nitride fieldeffect transistor (eGaN FET).

10. The DC-DC power converter of any one of embodiments 1 to 9, furthercomprising one or more capacitors disposed over the top side of theupper PCB part.

11. The DC-DC power converter of any one of embodiments 1 to 10, furthercomprising a core disposed between the top side of the lower PCB partand the bottom side of the upper PCB part, wherein the core has one ormore pockets formed therein, and wherein the embedded circuitry isdisposed in the one or more pockets.

12. The DC-DC power converter of any one of embodiments 1 to 11, whereinthe DC-DC power converter has a footprint that is smaller than 25 mm².

13. The DC-DC power converter of any one of embodiments 1 to 11, whereinthe DC-DC power converter has a footprint that is smaller than 10 mm².

14. The DC-DC power converter of any one of embodiments 1 to 11, whereinthe DC-DC power converter has a footprint that is smaller than 5 mm².

15. The DC-DC power converter of any one of any one of embodiments 1 to14, wherein the DC-DC power converter has a footprint that is as smallas 2 mm².

16. The DC-DC power converter of any one of embodiments 1 to 15, whereinthe DC-DC power converter has a footprint area that is between 0.5 and10 mm² per amperage of current.

17. A direct current to direct current (DC-DC) power converter packagecomprising:

-   -   an integrated circuit (IC) chip embedded in at least one printed        circuit board (PCB), the IC chip comprising a driver;    -   an inductor positioned outside of the chip embedded package and        coupled to a surface of the chip embedded package; and    -   a via electrically coupling the inductor to the IC chip;    -   wherein a footprint of the inductor overlaps, at least        partially, with a footprint of the IC chip.

18. The DC-DC power converter of embodiment 17, wherein a transistor isembedded in the at least one PCB, and wherein the inductor iselectrically coupled to the transistor.

19. The DC-DC power converter of any one of embodiments 17 to 18,wherein the IC chip comprises:

-   -   a pulse width modulator (PWM) controller coupled to the driver;        and    -   a switching transistor coupled to an output of the driver.

20. The DC-DC power converter of any one of embodiments 17 to 19,further comprising a switch comprising enhanced gallium nitride (eGaN).

21. The DC-DC power converter of any one of embodiments 17 to 20,wherein the switch is configured to switch at 4 MHz or faster.

22. The DC-DC power converter of any one of embodiments 17 to 20,wherein the switch is configured to switch at 5 MHz or faster.

23. The DC-DC power converter of any one of embodiments 17 to 19,further comprising a switch comprising at least one of silicon orgallium arsenide.

24. A direct current to direct current (DC-DC) power converter in asingle package comprising:

-   -   an enhanced gallium nitride (eGaN) component embedded, at least        partially, inside of a mounting substrate;    -   an inductor mounted outside of the mounting substrate; and    -   a via coupling the inductor to the eGaN component;    -   wherein a footprint of the inductor overlaps, at least        partially, with a footprint of the eGaN component.

25. The DC-DC power converter of embodiment 24, wherein the mountingsubstrate is a multi-layer PCB.

26. The DC-DC power converter of any one of embodiments 24 to 25,wherein the eGaN component is a switch comprising eGaN, the DC-DC powerconverter further comprising a driver circuit configured to drive theswitch.

27. The DC-DC power converter of any one of embodiments 24 to 26,wherein the driver and the switch are part of an IC chip.

28. The DC-DC power converter of any one of embodiments 24 to 27,wherein the IC chip further comprises a pulse width modulator (PWM)controller.

29. A direct current to direct current (DC-DC) power converter utilizinga chip embedded package, the DC-DC converter comprising:

-   -   an enhanced gallium nitride (eGaN) switch inside of a printed        circuit board (PCB);    -   a pulse width modulator (PWM) controller;    -   a driver embedded inside of the PCB, wherein the PWM controller        and the driver are configured to drive the eGaN switch at a        frequency of 1 MHz or higher;    -   an inductor positioned outside of the chip embedded package and        coupled to a surface of the PCB; and    -   a via electrically coupling the inductor to the eGaN switch.

30. The DC-DC power converter of embodiment 29, wherein the driver isconfigured to drive the eGaN switch at a frequency of 5 MHz or higher.

31. A direct current to direct current (DC-DC) power convertercomprising:

-   -   a printed circuit board; and    -   an integrated circuit inside of the printed circuit board, the        integrated circuit comprising a driver.

32. The DC-DC power converter of embodiment 31, further comprising aninductor electrically coupled to the integrated circuit by one or morevias that extend through the printed circuit board.

33. The DC-DC power converter of embodiment 32, wherein the inductor hasa footprint that at least partially overlaps a footprint of theintegrated circuit.

34. A direct current to direct current (DC-DC) power convertercomprising:

-   -   an integrated circuit comprising a driver; and    -   an inductor vertically stacked above the integrated circuit such        that a footprint of the inductor overlaps, at least partially,        with a footprint of the integrated circuit, wherein the inductor        is electrically coupled to the integrated circuit.

35. The DC-DC converter of embodiment 34, further comprising a printedcircuit board (PCB) having a first side and a second side that isopposite the first side, wherein the integrated circuit is mounted onthe first side of the PCB, and wherein the inductor is mounted on thesecond side of the PCB.

36. The DC-DC converter of embodiment 35, wherein the inductor iselectrically coupled to the integrated circuit by one or more vias thatextend through the printed circuit board.

37. A direct current to direct current (DC-DC) buck convertercomprising:

-   -   one or more switches;    -   a driver configured to drive the one or more switches; and    -   an inductor electrically coupled to the switches;    -   wherein the footprint of the DC-DC buck converter is less than        65 mm²;    -   wherein the DC-DC buck converter is configured to receive at        least 20 amps of current; and    -   wherein the DC-DC buck converter is configured to output at        least 20 amps of current.

38. A direct current to direct current (DC-DC) power convertercomprising:

-   -   one or more switches;    -   a driver configured to drive the one or more switches at a        frequency, the frequency being between 1 and 5 MHz inclusive;        and    -   an inductor electrically coupled to the one or more switches;    -   wherein the footprint of the DC-DC converter is less than or        equal to 10 mm²;    -   wherein the DC-DC converter is configured to receive at least 5        amps of current;    -   wherein the DC-DC converter is configured to output at least 5        amps of current.

39. A direct current to direct current (DC-DC) power convertercomprising:

-   -   a first switch coupled to a first inductor;    -   a second switch coupled to a second inductor; and    -   an integrated circuit chip embedded in a printed circuit board;    -   wherein the first switch and the second switch are coupled to a        modulator; and    -   wherein the first inductor and the second inductor are coupled        to a voltage output node.

40. The direct current to direct current (DC-DC) power converter ofembodiment 39, wherein the modulator is included in the integratedcircuit chip.

41. The direct current to direct current (DC-DC) power converter of anyone of embodiments 39 to 40, wherein the modulator is configured tocause the first switch and the second switch to operate output of phasewith a synchronous period.

42. The direct current to direct current (DC-DC) power converter of anyone of embodiments 39 to 41, wherein an output signal at the output nodeis a superposition of a first signal through the first inductor and asecond signal through the second inductor.

43. A direct current to direct current (DC-DC) power convertercomprising:

-   -   an integrated circuit chip embedded in a printed circuit board,        the integrated circuit chip comprising a driver;    -   a first switch coupled to the driver;    -   an inductor coupled to the first switch; and    -   a feedback path from an output node to a modulator circuit.

44. The direct current to direct current (DC-DC) power converter ofembodiment 43, wherein the modulator circuit is a voltage mode modulatorcircuit.

45. The direct current to direct current (DC-DC) power converter of anyone of embodiments 43 to 44, wherein the modulator circuit is a constanton time or constant off time modulator circuit.

46. The direct current to direct current (DC-DC) power converter of anyone of embodiments 43 to 45, wherein the modulator circuit is includedin the integrated circuit chip.

47. The direct current to direct current (DC-DC) power converter of anyone of embodiments 43 to 46, wherein the modulator circuit and theinductor are included in a package with the integrated circuit chip.

48. A direct current to direct current (DC-DC) power convertercomprising:

-   -   an integrated circuit chip embedded in a printed circuit board,        the integrated circuit chip comprising a driver;    -   a first switch coupled to the driver;    -   an inductor coupled to the first switch;    -   a feedback path from an output node to a modulator circuit; and    -   a ramp generator.

49. The direct current to direct current (DC-DC) power converter ofembodiment 48, wherein the feedback path and an output from the rampgenerator are coupled to a comparator.

50. The direct current to direct current (DC-DC) power converter ofembodiment 49, further comprising a reference voltage source coupled tothe comparator.

51. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 50, wherein the ramp generator is configured toemulate a ripple current through the inductor.

52. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 51, wherein the ramp generator comprises:

-   -   a first current source;    -   a second current source; and    -   a capacitor.

53. The direct current to direct current (DC-DC) power converter ofembodiment 52, wherein the first current source and the second currentsource are configured to be trimmed based, at least in part, on aninductance of the inductor.

54. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 53, wherein the ramp generator and the inductorare included in the same DC-DC power converter package.

55. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 54, wherein the ramp generator is configured togenerate an output signal that is unaffected by an output capacitorcoupled to the inductor.

56. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 55, wherein the ramp generator is configured togenerate an output signal that is independent from the equivalent seriesresistance (ESR) of an output capacitor coupled to the inductor.

57. The direct current to direct current (DC-DC) power converter of anyone of embodiments 48 to 56, further comprising an output capacitorhaving a sufficiently low ESR such that a ripple voltage across theoutput capacitor is too small to reliably provide to a modulationcircuit.

58. A ramp generator comprising:

-   -   a first current source coupled to a supply voltage;    -   a second current source coupled to ground; and    -   a capacitor coupled between the first current source and the        second current source.

59. The ramp generator of embodiment 58, wherein the ramp generator isconfigured to emulate a ripple current through an inductor in a DC-DCconverter.

60. The ramp generator of any one of embodiments 58 to 59, wherein theoutput of the first current source is based, at least in part, on aninput voltage to a DC-DC converter.

61. The ramp generator of any one of embodiments 58 to 60, wherein theoutput of the first current source is based, at least in part, on aninductance of an inductor in a DC-DC converter.

62. The ramp generator of any one of embodiments 58 to 61, wherein theoutput of the second current source is based, at least in part, on aninductance of an inductor in a DC-DC converter.

63. The ramp generator of any one of embodiments 58 to 62, wherein theoutput of the second current source is based, at least in part, on aninductance of an inductor in a DC-DC converter.

64. The ramp generator of any one of embodiments 58 to 63, wherein thefirst current source is configured to be trimmed based, at least inpart, on an inductance of an inductor in a DC-DC converter.

65. The ramp generator of any one of embodiments 58 to 64, wherein thesecond current source is configured to be trimmed based, at least inpart, on an inductance of an inductor in a DC-DC converter.

66. A method for making a chip embedded direct current to direct currentconverter comprising:

-   -   embedding an integrated circuit chip in a printed circuit board;    -   coupling a first inductor to the printed circuit board; and    -   coupling a second inductor to the printed circuit board, the        first inductor and the second inductor both coupled to an output        node.

67. A method for converting first direct current voltage to a seconddirect current voltage comprising:

-   -   driving a first switch coupled to a first inductor;    -   driving a second switch coupled to a second inductor, wherein        the first switch and the second switch are coupled to an output        node; and    -   modulating the driving of the first switch and the second switch        out of phase;    -   wherein at least one of a driver or a modulator is included in a        chip embedded in a printed circuit board.

68. A method for making a chip embedded direct current to direct currentconverter comprising:

-   -   embedding an integrated circuit chip in a printed circuit board;    -   coupling an inductor between the integrated circuit chip and an        output node; and    -   providing a feedback path from the output node to a modulator        circuit, wherein the modulator circuit includes a ramp        generator.

69. The method of embodiment 68, wherein the modulator circuit isincluded in the printed circuit board.

70. The method of any one of embodiments 68 to 69, wherein the modulatorcircuit is a constant on time or constant off time modulator circuit.

71. The method of any one of embodiments 68 to 70, wherein the rampgenerator is included in the integrated circuit.

72. The method of any one of embodiments 68 to 71, further comprising:

-   -   trimming the ramp generator based at least in part on the        property of the inductor.

73. The method of any one of embodiments 68 to 72, wherein the rampgenerator is the ramp generator of any one of embodiments 58 to 65.

74. A method for using a direct current to direct current convertercomprising:

-   -   receiving input power at an input node;    -   providing power through a switch to an inductor;    -   storing energy in an output capacitor such that an output        voltage forms across the output capacitor;    -   providing output power at the output voltage to an output node;    -   providing the output voltage to a modulator circuit;    -   generating a ripple voltage that is independent of an output        capacitor;    -   providing the ripple voltage to the modulator circuit;    -   modulating the switch based at least in part on an output of the        modulator circuit.

75. The method of embodiment 74, further comprising comparing at leasttwo of: the ripple voltage, a reference voltage, and the output voltage.

76. The method of any one of embodiments 74 to 75, further comprisingtrimming a current source based at least in part on an inductance of theinductor.

77. The method of any one of embodiments 74 to 76, wherein the ripplevoltage is generated by a ramp generator configured to emulate a currentthrough the inductor.

78. A direct current to direct current (DC-DC) power converter packagecomprising:

-   -   an integrated circuit (IC) chip embedded in at least one printed        circuit board (PCB), the IC chip comprising a driver;    -   an inductor positioned outside of the chip embedded package and        coupled to a surface of the chip embedded package; and    -   an overcurrent protection circuit configured to detect when a        current provided to the inductor exceeds a limit.

79. The direct current to direct current (DC-DC) power converter packageof embodiment 78, wherein:

-   -   the overcurrent protection circuit comprises a current source        configured to be adjusted or trimmed based at least in part on        an Inter-Integrated Circuit or Power Management Bus command;    -   a saturation inductance of the inductor exceeds the limit and        exceeds the limit by less than 50%;    -   the limit exceeds a maximum specified DC current specification        plus maximum alternating current ripple specification by less        than 50%.

80. A direct current to direct current (DC-DC) power converter packagecomprising:

-   -   an integrated circuit (IC) chip embedded in at least one printed        circuit board (PCB), the IC chip comprising a driver;    -   an inductor positioned outside of the chip embedded package and        coupled to a surface of the chip embedded package; and    -   an Inter-Integrated Circuit or Power Management Bus.

81. A direct current to direct current (DC-DC) power converter packageof embodiment 80, wherein:

-   -   the Inter-Integrated Circuit or Power Management Bus is coupled        to at least one current source and configured to provide a        protocol command to adjust or trim the current source.

82. A direct current to direct current (DC-DC) power converter packageof any one of embodiments 80 to 81, wherein:

-   -   the Inter-Integrated Circuit or Power Management Bus is coupled        to at least one current source and configured to provide a        protocol command to set or adjust a reference value provided to        a comparator.

83. A direct current to direct current (DC-DC) power converter packageof any one of embodiments 80 to 82, wherein the Inter-Integrated Circuitor Power Management Bus is configured to communicate protocolscomprising instructions to perform at least one of:

-   -   turn on or off the DC-DC power converter package, change a low        power or sleep mode of the DC-DC power converter package, read        out information about current settings of the DC-DC power        converter package, read out diagnostic and/or technical        information about the DC-DC power converter package, set or        change an output voltage provided by the DC-DC power converter        package.

84. A direct current to direct current (DC-DC) power converter packageof any one of embodiments 80 to 83, wherein a Power Management Protocolis implemented as an interconnect layer on top of an Inter-IntegratedCircuit implementation.

Example Isolated Topology

FIG. 20 shows an example circuit level schematic of a chip embeddedDC-DC converter package 2000 with an isolated topology. The schematicshows a power a power source 103, an AC ground 2003, a DC ground 2001,an output capacitor 111, an integrated circuit (IC) chip 113A, analternative IC 113B, a driver 117, a pulse width modulator (PWM)controller 119, a first switch (e.g., a first enhanced gallium nitride(eGaN) switch) 123, a second switch (e.g., a second eGaN switch) 127,capacitors 2005 and 2007, diodes D1 and D2, and inductor L4. Theschematic also shows an isolation circuit 2009 including a firstinductor L1, a second inductor L2, and a third inductor L3. The switches123, 127 can also be referred to as power switches, switching FETs,and/or switching transistors. In some cases an input capacitor 105 (notshown in FIG. 20) can be used, similar to FIG. 1.

The circuit in FIG. 20 can operate similarly to the circuit shown inFIG. 1, or any of the other embodiments disclosed herein. A differencebetween the circuit in FIG. 20 and the circuit in FIG. 1 is that theconfiguration in FIG. 20 is an isolated topology that includes anisolation circuit 2009 (e.g., in an isolated half bridge configuration).The voltage output port 109 can be electrically isolated from the powersource 103 such that there is no direct, electrically conductive pathwaytherebetween. Instead, the inductors L1, L2, and L3 can beelectromagnetically coupled such that a current through inductor L1(e.g., a changing current) can generate and impose a magnetic field oninductors L2 and L3, thereby causing a current to flow through inductorL4 (e.g., a changing current). The current through inductor L4 can causea charge to collect on the plates of capacitor 111 such that a voltageforms across the capacitor 111. Diodes D1 and D2 can be used to directthe current flow in one direction. In some embodiments, the diodes D1and D2 can be replaced with switches (e.g., MOSFETs), which can resultin greater efficiency, or with other electronic devices.

Although the isolation topology in FIG. 20 includes magnetically coupledinductors L1, L2, and L3, having the number of turns N_(P), N_(S1), andN_(S2), respectively, in the isolation circuit 2009, other embodimentscan include other configurations and other types of isolation circuittopologies, such a flyback, forward converter, two transistor forward,LLC resonant converter, push-pull, full bridge, hybrid, PWM-resonantconverter, or other design. Other layouts disclosed herein, such as thelayouts shown in FIG. 12, FIG. 13A, and FIG. 13B, can also be modifiedto use isolated topologies. In some embodiments, two in inductors can beused for the isolation circuit 2009. Although two examples ofalternative integrated circuits 113A and 113B are shown, othervariations can include any number of integrated circuits that includeany combination of the elements shown in integrated circuit 113B.

Example DC-DC Converters with Wireless Communication Systems

FIG. 21A shows an example DC-DC converter 2101 with a wirelesscommunication system 2103 in a package 2105. The DC-DC converter 2101can be any DC-DC converter described herein. The DC-DC converter 2101can be configured to receive an input voltage Vin and provide an outputvoltage Vout.

A wireless communication system 2103 can be included in a same packagethat the DC-DC converter 2101 is included in, or in a separate packagein some cases. The wireless communication system 2103 can be, forexample, a Wi-Fi system, a Bluetooth system, a radio frequency system,etc. The wireless communication system can include (not shown) anantenna, oscillator, driver, controller, firmware, processor, buffer,digital to analog converter, etc. The wireless communication system canalso include a wired communication input/output interface (shown as theComm I/O) that can connect to other devices such as a CPU (for example,as shown in FIG. 22) so that the CPU can send and receive wirelesssignals through the wireless communication system 2103.

The wireless communication system 2103 can also or alternatively includea communication path (e.g., shown as the PWR Control line) with theDC-DC converter 2101 to control power parameters of the DC-DC converter.In some embodiments, the wireless communication system 2103 can coupleto the DC-DC converter over a PMBUS. Accordingly, the DC-DC converter2101 can respond to wireless instructions received through the wirelesscommunication system 2103 (e.g., via a Wi-Fi, Bluetooth, broadband, orother type of wireless signal), such as to turn on, turn off, to enter asleep mode, to reset, to clear faults, to change or set an outputvoltage, to control or limit an output current, to enter a differentmode of operation, etc. The DC-DC converter 2101 can also wirelessreport or broadcast information regarding the health of the DC-DCconverter, such as telemetry, an input voltage, an output voltage, aninput current, an output current, a temperature, etc.

The wireless communication system 2103 can be included in a same package2105 as the DC-DC converter 2101, or in a separate package, in somecases. The wireless communication system 2130 can be powered by theDC-DC converter 2101 and receive the output voltage Vout generated bythe DC-DC converter 2101. For example, the DC-DC converter can beconfigured to receive a 120 volt DC input and provide a 10 volt DCoutput more suitable for some electronic devices, and the wirelesscommunication system can be configured to use the 10 volt DC output fromthe DC-DC converter. In some embodiments, by including both the wirelesscommunication system 2103 and the DC-DC converter 2101 in the samepackage 2105, the overall area occupied by these components can bereduced.

FIG. 21B shows an example DC-DC converter 2101 with a wirelesscommunication system 2103 in a package 2105. The DC-DC converter can beconfigured to receive an input voltage Vin and provide an output voltageVout. The wireless communication system can also be powered by the inputvoltage Vin.

The wireless communication system can be powered by the input voltageVin. For example, the DC-DC converter 2101 can be configured to receivea 10 volt input and provide a 25 volt output. The wireless communicationsystem 2103 can also be powered through the 10 volt input. The wirelesscommunication system 2103 can interact with the DC-DC converter 2101and/or other devices as described with respect to FIG. 21A (PWR CTRL andComm I/O lines are not re-shown in FIG. 21B).

FIG. 21C shows an example package 2105 including a wirelesscommunication system 2103 and two DC-DC converters 2101, 2102. A firstDC-DC converter 2101 can be configured to receive an input voltage Vinand provide a first output voltage Vout1. A second DC-DC converter 2012can be configured to receive the input voltage Vin and provide a secondoutput voltage Vout2. The first and second output voltages can bedifferent. A wireless communication module 2103 is configured to bepowered by the second DC-DC converter 2102.

For example, the first DC-DC converter 2101 can be configured to receivea 60 volt input and provide a 120 volt output. The second DC-DCconverter 2102 can be configured to receive the 60 volt input andprovide a 5 volt output. The wireless communication system 2103 can bepowered by the 5 volt output from the second DC-DC converter 2102. Thewireless communication system 2103 can interact with both of the DC-DCconverters 2101, 2102 and/or other devices as described with respect toFIG. 21A (PWR CTRL and Comm I/O lines are not re-shown in FIG. 21C).

FIG. 21D shows an example embodiment of a power supply 2101 with anintegrated wireless communication system 2103. The power supply 2101 canbe a DC-DC converter, an AC-DC converter, a linear mode power supply, ora switch mode power supply, or any other suitable type of power supply.The power supply 2101 can use isolated topology or non-isolatedtopology, and can use high or low voltages. The power supply 2101 canuse any combination of suitable features disclosed herein. In theembodiments illustrated in FIG. 21D, the power supply 2101 can be aDC-DC converter configured to receive an input voltage (Vin) (e.g., froma battery) and to output a different output voltage Vout. In someembodiments, the power supply 2101 can be an AC to DC converter, whichcan receive an AC signal (Vin) and output a DC signal (Vout). An outputcapacitor can be used, as discussed herein. The power supply 2101 cansupply power to one or more loads on a device (e.g., shown in FIG. 21Das a resistor). The device can be an electrical appliance (e.g., homeelectronics) such as a smart TV, an oven, a toaster, a coffee machine,etc., or the device can be industrial equipment, an internet of things(IoT) device, etc.

A wireless device 2115 can be in communication with the power supply2103. A wireless communication system 2117 of the wireless device 2115can be similar to the wireless communication system 2103 of the powersupply 2101. In some embodiments, the wireless device 2115 can include apower supply 2101 (e.g., a DC-DC converter or an AC-DC converter) havinga wireless communication system (e.g., integrated therewith). Thewireless device 2115 can be a smartphone, tablet computer, a wirelessrouter or access point in communication with a remote device, etc. Thepower supply 2101 can be part of a local network to enable one or morewireless devices 2115 to communication with the power supply 2101. Thewireless device 2115 can send or receive information or commands to orfrom the power supply 2101 (e.g., via a Wi-Fi, Bluetooth, broadband, orother type of wireless signal). The wireless device 2115 can command thepower supply to turn on or off, to enter a sleep mode (e.g., to reducestandby power consumption), clear faults, reset the power supply (e.g.,in the event of a fault condition), control voltage or current levels,change modes of operation, etc. The power supply 2103 can communicationinformation to the wireless device 2115, such as fault conditions, modeof operation, voltage and/or current settings (e.g., limits),information relating to the health of the power supply 2101 (e.g.,temperature). The wireless device 2115 can send commands through thewireless communication system 2013 of the power supply 2101 to controlthe device associated with the power supply, such as a command to thedevice to turn on, turn off, change a setting, perform an action, etc.For example, a coffee maker can receive a command from the wirelessdevice 2115 to start making coffee via a wireless communication system2103 that can be integrated with or coupled to the power supply 2101,such as when a wireless device 2115 determines that a user is goinghome. The device associated with the power supply (e.g., a coffee maker)can send information about itself (e.g., settings, current mode ofoperation, previously performed actions, that coffee is ready, systemstatus, errors, etc.) to the wireless device 2115 via the wirelesscommunication system 2103 integrated with the power supply 2101.Accordingly, the device associated with the power supply (e.g., a coffeemaker) can use the wireless communication system 2103 that is includedin or integrated with the power supply 2101 without having a second,separate wireless communication system.

FIG. 21E shows an example DC-DC converter with a wireless communicationsystem 2103 (which can, in some embodiments, be incorporated into apackage 2105). The DC-DC converter can be configured to receive an inputvoltage Vin and provide an output voltage Vout. The DC-DC converter caninclude a PWM controller 119, driver 117, switches 2109, an inductor131, and a capacitor 111. Some portions of the DC-DC converter alreadyshown in other figures or discussed in other embodiments (such as thefeedback system, multiple inductors, etc.) can be present but not shownin FIG. 21E for clarity.

One or more system components can be included in an integrated circuit2107 (e.g., which can be an eGaN IC). The integrated circuit can includeany combination of the wireless communication system 2103, PWMcontroller 119, driver 117, and switches 2109. As indicated by thedotted lines, the integrated circuit can be divided into one or moreseparate integrated circuits that can include any combination of thewireless communication system 2103, PWM controller 119, driver 117, andswitches 2109. In some embodiments, there can be multiple integratedcircuit chips, including separate IC chips for each the wirelesscommunication system 2103, PWM controller 119, driver 117, and switches2109. In some embodiments, the integrated circuit can be an eGaN IC.Some embodiments can use a monolithic eGaN IC that includes all ormultiple ones of the wireless communication system 2103, PWM controller119, driver 117, and switches 2109. Some embodiments can also use aseparate eGaN ICs for each of the wireless communication system 2103,PWM controller 119, driver 117, and switches 2109, or any combinationsthereof. In some embodiments, the PWM controller 119 can be omitted fromthe package 2105. A separate PWM controller 119 can be used to driveseveral DC-DC converter power stages, as discussed herein (e.g., asshown in FIG. 24A).

The wireless communication system 2103 can communicate with the PWMcontroller to adjust, for example, the PWM signals provided to thedriver to set an output voltage and/or change current limits. In someembodiments, the wireless communication system can be configured toreceive signals from ammeters, voltmeters, thermometers, other sensors,and/or status report registers (not shown) configured to reportinformation about various parts of the circuit.

Example IoT Device

FIG. 22 shows an example Internet of Things (IoT) device 2200. The IoTdevice 2200 can include a package 2105 including a wirelesscommunication system 2103 and two DC-DC converters 2101, 2102 as shownin and described with respect to FIG. 21C. Various other configurations(e.g., similar to FIG. 21A, 21B, or 21D) can be used, such as having asingle DC-DC converter, or having a different type of power supply(e.g., an AC-DC converter). The IoT device can also include a firstsystem 2203. The IoT device can also include an electrical system 2201that can include, for example, a CPU 2205, RAM 2207, an I/O system 2209,and other electrical devices 2211. The IoT device 2200 can communicateover a network 2213 to a wireless device 2215 such as a smartphone.

In some embodiments, components in the electrical system 2201 andcomponents in the first system 2203 can use different voltages.Accordingly, the first and second DC-DC converters 2201, 2202 canprovide different voltages to different devices.

The electrical system 2201 can be configured to receive the Vout2voltage provided by the second DC-DC converter. The Vout2 voltage canbe, for example, a voltage appropriate for some electrical devices inthe electrical system and the wireless communication module. The firstsystem 2203 can include different components configured to receive adifferent voltage Vout1.

For example, in one embodiment, the IoT device 2200 is a programmablelighting system. The first system 2203 can include one or more lightbulbs configured to receive 60 V. The electrical system 2201 can beconfigured to turn the light bulbs on and off. A user can program anon/off schedule for the lights and/or issue commands to turn the lightson/off through the wireless communication system 2103. The receivedcommands can be transmitted from the wireless communication system 2013to the CPU 2205. The CPU 2205 can process the commands and turn thelights in the first system 2203 on and off according to the command. Theuser can wirelessly connect to the IoT device from another computer orsmartphone, etc., and can connect to the wireless communication system2103 directly or through a network such as the internet.

In another example of an IoT device, the first system 2203 can be, forexample, a mechanical system that receives a higher voltage and morepower than the electrical system in order to perform mechanical work,such as a motor. In other examples of IoT devices, the first system 2203can be any system, whether electrical, mechanical, chemical, thermal,etc. that receives a different voltage than one of the components in theelectrical system 2201. Other examples of IoT devices can includeinternet connected climate control systems, doors, computers, cameras,dispensers, cars, appliances, etc.

The wireless communication system 2103 can send and receive wirelesssignals to a wireless device 2215. In some embodiments, the wirelesssignals can be sent via a network 2213, such as the internet or awireless local area network. The wireless device 2215 can be, forexample, a smartphone, a computer, a desktop, another IoT device, etc.The wireless device 2215 can send/receive communications to/from the CPU2205 as wireless signals by way of the wireless communication system2103. In some embodiments, the wireless device can send/receive wirelesscommunications to/from either of the DC-DC converters by way of thewireless communication system 2103. Communications from the wirelessdevice 2215 can be transmitted between the wireless communication system2103 by way of a power control line (for example, like the PWR Controlline shown in FIG. 21A) such as a PMBUS between the wirelesscommunication system 2103 and either or both of the DC-DC converters2101, 2102.

Although FIG. 22 shows an example of an IoT device including a package2105 including a DC-DC converter and wireless communication system fromFIG. 21C, other IoT devices can include any packaged IoT device andwireless communication system, for example, as shown in FIG. 21A to FIG.21E. Additionally, IoT devices can include any number of other DC-DCconverters, with or without a wireless communication system in apackage, to provide additional voltages or currents to any number ofelectrical systems.

Multiple DC-DC Converters with Adjustable Output

FIG. 23A shows an example DC-DC converter system 2300 including multipleDC-DC converters 2303, 2305, 2307. In some embodiments, the DC-DCconverters 2303, 2305, 2307 can be included in a package 2301. In someembodiments, the DC-DC converters 2303, 2305, 2307 can be separatepackages. A user can combine any number of DC-DC converter packages toproduce various different amounts of current. In various embodiments,one or more components of the various DC-DC converters 2303, 2305, 2307,such as PWM controllers, drivers, and/or switches, can be combined andincluded in one or more integrated circuits. In some embodiments, eachof the DC-DC converters 2303, 2305, 2307 have their own separate IC'swith PWM controllers, drivers, and/or switches that are separate fromcomponents of the other DC-DC converters. In some embodiments, the DC-DCconverters 2303, 2305, 2307 can be interconnected to facilitate currentsharing between the DC-DC converters 2303, 2305, 2307. For example, afeedback system can use output from one of the DC-DC converters 2303,2305, 2307 to control one or more others of the DC-DC converters 2303,2305, 2307. For example, if the DC-DC converter 2303 is becomingoverloaded, a feedback system can cause the other DC-DC converters 2305,2307 to take more of the load to better balance the current between theDC-DC converters 2303, 2305, 2307.

The DC-DC converter system can be configured to receive an input voltageVin and generate an output voltage Vout. Each of the DC-DC converterscan be configured to generate the output voltage. Each of the DC-DCconverters 2303, 2305, and 2307 can also be coupled in parallel betweenthe system input and the system output. As a result of the parallelconfiguration, the total current supplied by the DC-DC converter system2300 can be the sum of the individual currents supplied by the DC-DCconverters 2303, 2305, 2307. The example in FIG. 23A shows a DC-DCconverter system 2300 where 3 DC-DC converters 2303, 2305, 2307 areconfigured to provide 10 amps of current, and the total output currentprovided by the DC-DC converter system 2300 is 30 amps. In someembodiments, six DC-DC converters providing 20 amps can be combined toprovide 120 amps, or any other suitable combination of power converterscan be used. In some embodiments, currents from a plurality of DC-DCconverters can combine to exceed 200 amps. Any number of DC-DCconverters can be combined in parallel to provide various differentamounts of current (e.g., 2, 3, 4, 5, 7, 10, 15, 20, 25, or more DC-DCconverters). In some embodiments, DC-DC converters configured to outputdifferent amounts of current can be combined. For example, 1 DC-DCconverter configured to output 20 amps can be combined with 1 DC-DCconverter configured to output 10 amps and 3 DC-DC converters configuredto output 2 amps, which can provide a current of 36 amps. The variousembodiments of DC-DC converts disclosed herein can be used as modularcomponents to be combined to form a wide variety of voltages and/orcurrents using only a small number of DC-DC converter types. Forexample, DC-DC converters configured to output 50 amps, 20 amps, 10amps, 5 amps, 2 amps, and 1 amp can be used in various differentcombination to provide systems that can output current amounts from 1amp to 100 amps using 6 or fewer DC-DC converters.

FIG. 23B shows an example DC-DC converter system 2350 including multipleDC-DC converters 2353, 2355, 2357. The DC-DC converters 2353, 2355, 2357can optionally be included in a package 2351. The system 2350 (e.g., thepackage 2351) can also include a controller 2209 and a switching system(e.g., with current sensors) 2361. In some embodiments, the variouscomponents in the system 2350 can be in separate packages.

The DC-DC converter system 2350 can be configured to receive an inputvoltage Vin and generate an output voltage Vout. Each of the DC-DCconverters can be configured to generate the output voltage. Each of theDC-DC converters 2303, 2305, and 2307 can be coupled in parallel betweenthe system input and the system output. As a result of the parallelconfiguration, the total current supplied by the DC-DC converter system2200 can be the sum of the individual currents supplied by the DC-DCconverters 2303, 2305, 2307.

A controller 2359 can be configured to receive commands from acommunication line (e.g., PMBUS), and in response to the command,configure arrangements and combinations of the DC-DC converters 2353,2355, 2357. The controller 2359 can cause different combinations of theDC-DC converters 2353, 2355, 2357 to contribute to the output. Forexample, the controller 2359 can configure all three DC-DC converters toprovide a maximum current such that a total of 35 amps are provided tothe output. In response to receiving a command to provide 15 amps, thecontroller 2359 can then configure each of the three DC-DC converters2353, 2355, 2357 to provide a combination of currents that add to 15amps (such as 5+5+5, 0+10+5, or a proportionally balanced60/7+30/7+15/7).

The switching system can be controlled by the controller 2359 to, forexample, open a connection in a parallel path between any of the DC-DCconverters 2353, 2355, 2357 and the output. For example, to provide 15amps, the switching system can decouple the 20 amp DC-DC converter 2353from the output while keeping the 10 amp DC-DC converter 2355 and the 5amp DC-DC converter 2357 coupled to the output. In some embodiments,functionality between the controller 2359 and the switching system 2361can be combined into one control/switching system. The system 2350(e.g., the switching system 2361) can include current sensors to detecta current output from each of the DC-DC converters 2353, 2355, 2357. Insome embodiments, the current sensors can be included in each of theDC-DC converters, and outputs from the current sensors can be providedas feedback to the controller 2359. In some embodiments, the currentsensors can be included in each of the DC-DC converters, and a feedbackand control system (such as OCP) can be included with each DC-DCconverter 2353, 2355, 2357 as shown in FIG. 1. Any number of DC-DCconverters can be combined, as discussed in connection with FIG. 23A.

In some embodiments, there can be feedback at the DC-DC converter system2350 level, wherein the outputs of each DC-DC converter 2353, 2355, 2357is sensed and provided to the controller 2359. The controller can (e.g.,based on the outputs of the DC-DC converters 2353, 2355, 2357) performcurrent balancing. Current balancing can include increasing ordecreasing a current output of each DC-DC converter 2353, 2355, and/or2357. The current balancing can include, for example, detecting that afirst DC-DC converter is at, reaching, or exceeding a threshold limit(e.g., a current output limit, an inductor saturation limit, a voltagelimit, a temperature limit), reducing the current provided by the firstDC-DC converter, and, in some cases, increasing a current provided by asecond DC-DC converter to compensate for the reduced current provided bythe first DC-DC converter. Current balancing can include, for example,increasing and/or decreasing the output current of one or more of theDC-DC converters 2353, 2355, and/or 2357 in response to variations in acurrent drawn by a load. For example, a motor in steady state can drawless current than a motor that is spinning up, and current balancing canbe performed to provide more or less current to the motor.

In some embodiments, the feedback at the DC-DC converter system 2350level can be used to detect a temperature and/or inductor saturation ofone of the DC-DC converters included in the system. In response to afirst DC-DC converter reaching a threshold temperature and/or having athreshold inductor saturation, the controller can reduce the currentprovided by the DC-DC converter and, in some cases, compensate byincreasing the current provided by a second DC-DC converter.

Some embodiments can include multiple DC-DC converters with differentamperage capacities. An example DC-DC converters system 2350 can includethree 10 amp DC-DC converters, and a controller can be configured toprovide a variable current output up to 30 amps. As another example, aDC-DC converters system 2350 can include four 1 amp DC-DC converters, a5 amp DC-DC converter, a 10 amp DC-DC converter, and a 20 amp DC-DCconverter. As another example, a DC-DC converters system 2350 caninclude a 5 amp DC-DC converter, a 10 amp DC-DC converter, and aplurality of 20 amp DC-DC converters. As another example, a DC-DCconverters system 2350 can include a plurality of DC-DC convertershaving a total current capacity of at least 50 amps, 100 amps, 150 amps,200 amps, or more. High amperage DC-DC converter systems can bedesigned, based at least in part, on the efficiency, improved size,switching speed, improved heat dispersion, and topologies disclosedherein.

In some embodiments, the configurations and layouts shown in FIG. 23Aand FIG. 23B can be arranged in a device without the packages 2301 and2351. For example, each DC-DC converter 2303, 2305, and 2307 can be anindividual package.

Multiple Power Stage Configuration

FIG. 24A shows a DC-DC converter 2400 with multiple power stages2403A-2403C. A PWM controller can be used to provide pulse widthmodulated signals to a plurality of power stages, which can each have adriver and one or more switches. Two or more DC-DC converter powerstages can share a single PWM controller. The topology shown in FIG. 24can be used, for example, in some implementations of the technology andprinciples discussed herein, such as shown and described with respect toFIG. 23A and FIG. 23B. Some portions of the DC-DC converter 2400 alreadyshown in other figures (such as the feedback system) can be present butnot shown in FIG. 24A. The DC-DC converter 2400 can include an outputcapacitor 111, a package 2401, an integrated circuit (IC) chip 2413,drivers 117A-117C, a pulse width modulator (PWM) controller 119,switches (e.g., eGaN switches) 2405A-2405C, and inductors 131A-131C.

In some embodiments, an IC 2413 can include the PWM controller 119,although the PWM controller 119 need not be part of an IC 2413 in otherembodiments. The PWM controller 119 can be separate from or external tothe package 2401 and provide PWM signals that are out of phase to eachof the drivers 117A-117C in the different power stages 2403A-2403C. Forexample, for three power stages, the PWM signals can be 120 degrees outof phase with each other. In some embodiments, the PWM controller 119can be separate from or external to a PCB in the package 2401 but stillincluded in the package 2401. In some embodiments the PWM controller 119can be part of the package 2401.

The package 2401 can include a plurality of power stages 2403A-2403C.Each power stage 2403A-2403C can have an integrated circuit that ischip-embedded in a PCB of the package. As an alternative embodiment, aplurality of power stages such as 2403A-2403C can be included in oneintegrated circuit as shown by the dotted line 2404.

Each power stage 2403A-2403C can include a driver 117A-117C and switches2405A-2405C as respectively shown. Each power stage 2403A-2403C can becoupled to a respective inductor 131A-131C. The power stages 2403A-2403Ccan be configured in parallel. The current capacity of DC-DC converter2400 can be the sum of the current capacity in each parallel branch ofpower stages 2403A-2403C and inductors 131A-131C.

FIG. 24B shows an example layout of inductors 131A-131C in DC-DCconverter 2400. The PWM controller 119 is not shown in FIG. 24B, forsimplicity. The three inductors 131A-131C can each have respectivefootprint 2423A-2423C, which can be included within a footprint ofpackage 2401. The footprints of the inductors can overlap with afootprint any of the integrated circuit chip 2404 and/or the powerstages 2403A-3403C. FIG. 24B is not exactly to scale, but nonethelessshows how inductor footprints can be laid out and occupy a majorityand/or substantial portion of a package 2401 footprint. In someembodiments, the inductors can be coupled to the package 2401 withoutbeing physically inside a package encapsulation. For example, aninductor can be coupled to and/or protrude from a top surface of apackage. For example, the package 2401 shown in FIG. 24A can end at thedotted line 2402.

Example Side Cross Sectional View

FIG. 25 shows an example side view of a DC-DC converter 2500. The DC-DCconverter includes a PCB 2501, an inductor 2503, a capacitor 2505, achip-embedded PWM controller 2507, a chip-embedded driver 2509,chip-embedded switches 2511, and a via 2513.

The inductor 2503 and capacitor 2505 can be external to the PCB 2501.The inductor can be coupled to the switches 2511 by way of a via 2513.

The PWM controller 2507 can be in a first integrated circuit (shown) ora first chip-embedded integrated circuit (not shown). In someembodiments, the PWM controller 2507 can be outside of the package 2501.The first integrated circuit can be based on any semiconductor material,such as silicon, and can be an eGaN IC.

The driver 2509 can be in a second chip-embedded integrated circuit. Thesecond integrated circuit can be based on any semiconductor material,such as silicon, and can be an eGaN IC.

The switches 2511 can be in a chip-embedded integrated circuit such asthe second chip-embedded integrated circuit or a third chip-embeddedintegrated circuit. The integrated circuit can be based on anysemiconductor material, such as silicon, and can be an eGaN IC.

In some embodiments, the second integrated circuit can be a monolithicIC that includes both the driver 2509 and the switches 2511. In someembodiments, the driver 2509 and the switches can be in separate IC's.In some embodiments, the PWM controller 2507, driver 2509, and switches2511 can be in a monolithic IC (e.g., an eGaN IC). In some embodiments,the PWM controller 2507 can drive multiple sets of divers 2509 andswitches 2511, as discussed herein.

Preventing Inductor Saturation

For inductors of the same physical size, an inductor designed to have ahigher saturation limit can also have an increased direct currentresistance (DCR). An inductor can also be designed to have a highersaturation limit without increasing the DCR, but the inductor's physicalsize will increase. For example, a first inductor rated for a 10 A limitand a 15 A saturation limit can have a DCR of 4 milliohms. A secondinductor (that is the same physical size as the first inductor) can alsohave a 10 A current rating and only a 3 milliohm DCR, but the secondinductor will have a lower saturation limit of 13 A. It can be desirableto use an inductor (such as inductor 131 of FIG. 1) with both a smallerphysical size and a lower DCR to improve efficiency without trading offone property (DCR or size) for the other, and to do so without violatingdesign principles by risking inductor saturation. A saturated inductorcan provide lower inductance and also act as an unintended short circuitbetween the input and output ports. Accordingly, to prevent inductorsaturation, in some cases a larger inductor having a larger inductanceand larger saturation limit can be used despite the increased DCR toensure that the inductor does not saturate. For example, an inductor canbe rated for 10 A, but the inductor can experience a 30% AC ripple suchthat the peak current is 11.5 A, and be exposed to temperaturevariations that affected the saturation limit. Accordingly, to preventinductor saturation under a variety of operable conditions, the 10 Ainductor can be designed with a 15 A or 20 A saturation limit to providea saturation buffer or margin of error. In some designs, a buffer isdesigned for a worst-case scenario, such as across a wide temperaturerange, such that an inductor is selected to have a saturation rating oftwice the current output rating of the DC-DC converter. However, suchdesigns can increase at least the physical size and/or DCR of theinductor.

In some embodiments, an inductor having a lower DCR can be used toimprove efficiency without incurring the effects of inductor saturation.For example, a DC-DC converter rated for 10 A of output current can usean inductor rated for 11 A, 10.5 A, 10.25 A, 10.1 A, etc. In some casesan inductor can have a current rating and a saturation rating, which canbe higher than its current rating. The DC-DC converter can have aninductor having a saturation limit that is 0%, 5%, 10%, 20%, 30%, 40%,50%, 75%, or 100% higher than the current rating of the inductor or ofthe DC-DC converter, or any values therebetween, or any ranges boundedby any combination of these values, although values outside these rangescan be used in some implementations.

The DC-DC converter can include an overcurrent protection system. Asshown in FIG. 1, a first input of a comparator 139 can be coupled to acurrent source 137, which can be used as a reference for setting anovercurrent limit. An I²C and/or PMBUS (described with respect to FIG.2) can be used to trim and/or adjust the output current of currentsource 137. Accordingly, an overcurrent limit can be set and/oradjusted. The output of the comparator 139 can be provided to faultlogic and overcurrent protection (OCP) circuitry 141.

The comparator 139 can detect when the inductor 131 is nearing or at thesaturation limit. The current source 137 can act to provide thereference current for comparison. The current source 137 can be trimmedand/or controlled (e.g., via a PMBUS or other control communicationline) to adjust the reference current. Accordingly, the thresholdreference value can be adjusted for different inductors 131 and acrossdifferent temperatures (which can be in response to a signal from athermometer, not shown). In response to an overcurrent event (e.g., asdetected by the comparator 139), the fault logic 141 can activateovercurrent protection circuitry. This can, for example, cause the PWMcontroller and/or driver to (or to directly) open switches 123 and closeswitch 127, or otherwise prevent excess voltage or current from reachingthe output. When the overcurrent protection is no longer detected (withhysteresis in some embodiments), the switches 123 and 127 can resumenormal operation.

In some example embodiments, buffer room of less than 50%, 25%, 15%,10%, 5%, 2.5%, or 1% can be set, or any values therebetween, or anyranges bounded by any combination of these values, although bufferamounts outside these ranges can be used in some implementations. Thelow buffer room can be used even across a wide range of temperatureconditions. For example, a 10 A rated DC-DC converter can use aninductor with a 10.5 A saturation limit (e.g., buffer of 5%) and operateunder temperature conditions ranging from −40° C. to +125° C. Otherexample minimum to maximum temperature ranges can include 0° C. to 100°C., 10° C. to 90° C., 25° C. to 75° C., and the like. Other exampletemperature ranges include at least 50° C. of variation, at least 75° C.of variation, at least 100° C. of variation, at least 125° C. ofvariation, at least 150° C. of variation, at least 165° C. of variation,and at least 175° C. of variation.

The overcurrent detection and protection functions can be performedunder a variety of conditions. For example, the overcurrent detectionand protection can be calibrated for each inductor included in the DC-DCconverter. I²C communications over the PMBUS (or any other suitablecontrol communication protocol or physical layer) can be used to adjustor calibrate the reference current 137 for the inductor. In someembodiments, a lookup table or other memory structure can store atemperature profile for the inductor 131 and trim the current source 137to provide the appropriate reference current to the comparator 139.

AC-DC and Other Types of Power Converters

The teachings and principles disclosed herein can be applied to any typeof power converters, not just DC to DC converters. DC to AC converters,AC to DC converters, and AC to AC converters can also use the teachingsand principles disclosed herein. For example, FIG. 26A shows an exampleblock diagram 2600 of an AC to DC converter. The AC to DC converter 2600is configured to receive an AC input voltage and provide a DC outputvoltage. The AC to DC converter 2600 can include a filter 2601, anisolation circuit 2603, a rectifier circuit 2605, and/or a smootherand/or output filter 2607.

The filter 2601 can be, for example, a bandpass filter configured topass voltage signals within frequency range (e.g., 50-60 Hz). The filtercan include one or more switches, inductors, and/or capacitors. In someembodiments, the filter 2601 can be omitted.

An isolation circuit 2603 can be configured to electrically isolate theAC input port from the DC output port such that there is no direct,electrically conductive pathway therebetween. In some embodiments, theisolation circuit can be arranged in a different place, such as towardthe output, after the AC signal has been converted to a DC signal. Byway of example, the inductors L1 and L2 can be electromagneticallycoupled such that a current (e.g., a changing current (AC)) throughinductor L1 can generate and impose a magnetic field on inductor L2,thereby inducing a current (e.g., a changing current (AC)) throughinductor L2. The inductors L1 and L2 can provide a transformer to stepdown a higher AC voltage to a lower AC voltage. In some embodiments, thetransformer (e.g., the isolation circuit 2603) can be omitted, such asif the input AC voltage does not need to be reduced.

A rectifier 2605 can include an arrangement of diodes 2609 and/or activeswitches 2611. Various types of rectifier topologies include half bridgerectifiers, full bridge rectifiers, single phase rectifiers, multi-phaserectifiers, active rectifiers, etc. can be used. Active rectifiers caninclude one or more active switches 2611. In some embodiments, a diodebridge can be used to convert the AC signal into a pulsed DC signal. Theswitches 2611 can be actively controlled. In some embodiments, a PWMcontroller can be included and provide PWM signals to control theswitches 2611.

A smoother and/or output filter 2607 can include an LC network. The LCnetwork can include an inductor L3 and capacitor C1. In someembodiments, the inductor L3 can be omitted. The smoother and/or outputfilter 2607 can include a reservoir capacitor, which can smooth thepulsed DC signal into a smoother DC signal.

The technology described herein can be applied to the various componentsof the AC-DC converter in FIG. 26A. For example, any combination ofcircuit elements, such as the active switches 2611, any control system(e.g., a PWM controller) for the active switches 2611, and diodes 2609can be included in a chip embedded integrated circuit and coupled toinductors L1, L2, and/or L3 by way of a via. Any functional stage of theAC-DC converter such as the filter 2601, isolation circuit 2603,rectifier 2605, and smoother & output filter 2607 can be included in onechip-embedded integrated circuit or any number of chip-embeddedintegrated circuits. Any of the inductors (such as L1, L2, and L3) orcapacitors (such as C1, or the reservoir capacitor) can be stacked above(e.g., at least partially or completely overlapping) the embeddedcircuitry (e.g., the integrated circuit) and can be coupled to theintegrated circuit by way of one or more vias. The physical layout caninclude the techniques discussed with respect to FIG. 3. Any of thefeedback and control techniques disclosed herein can also be applied.

FIG. 26B shows an example embodiment of an AC to DC converter. The AC-DCconverter can receive an input AC signal (e.g., Vin). Optionally,voltage modification circuit can, such as a transformer 2603, can changethe voltage level of the input AC signal. For example the transformer2603 can be configured to step down the input AC voltage to a reduced ACvoltage. The transformer 2603 can include two inductors, as discussedherein. The transformer 2603 can be omitted, in some embodiments. TheAC-DC converter can include a rectifier circuit 2605, which can beconfigured to convert the AC signal into a pulsed DC signal. In theembodiment illustrated in FIG. 26B, a full bridge rectifier circuit(e.g., having four diodes) can be used. Various types of rectifiercircuits can be used, such as a diode bridge, a half-wave rectifier, afull-wave rectifier, a half bridge rectifier, etc. In some embodiments,the rectifier circuit can include one or more diodes. The AC-DCconverter can include a smoothing circuit 2607. In some embodiments, thesmoothing circuit 2607 can include a capacitor (as can be seen in FIG.26B), which can be used as a reservoir capacitor. In some embodiments,the smoothing circuit can include an inductor, or an LC circuit thatincludes both an inductor and a capacitor. The smoothing circuit 2607can smooth the pulsed DC signal to produce a more steady DC voltage(Vout). The output DV voltage (Vout) can be used to supply current toone or more loads on a device (e.g., shown here as a resistor).

FIG. 26C shows an example embodiment of an AC-DC converter. The optionalvoltage modifier 2603 can include a transformer (e.g., having twoinductors), as discussed herein. In some embodiments, the rectifiercircuit 2605 can include one or more switches 2622, which can be drivento allow and block current to rectify the AC signal (e.g., to produce apulsed DC signal). The switches 2622 can be MOSFET switches. Theswitches 2622 can be eGaN switches. The switches 2622 can besynchronized with the AC signal. In some embodiments, a PWM controller2626 and/or a driver 2624 can be used to drive the switches 2622. Afeedback system 2628 can be used, similar to the other embodimentsdisclosed herein. In some embodiments, a combination of diodes andswitches can be used for the rectifier circuitry in the AC-DC converter.The smoothing circuit 2607 can be configured to smoother the voltage, asdiscussed herein and can include a capacitor and/or and inductor.

In some embodiments, the rectifier circuitry 2605 can be embedded in aPCB, as described herein. The rectifier circuitry 2605 can be in one ormore integrated circuits (ICs). For example, chip embedded circuitry2640 (e.g., one or more ICs) can include any combination of the PWMcontroller 2626, the driver 2624, and the one or more switches 2622. Insome embodiments, some or all of the feedback system 2628 can be part ofthe embedded circuitry 2640 (e.g., on the one or more ICs). In someembodiments, the PWM controller 2626 can be omitted. In some cases, anexternal PWM controller can be used for multiple AC-DC converters,similar to the discussion herein. The embedded circuitry 2640 caninclude one or more diodes, which can be configured to rectify the ACsignal into a pulsed DC signal. One or more inductors and/or capacitors(e.g., forming part of the transformer 2603 and/or the smoothingcircuitry) can be disposed outside the PCB, and can be electricallycoupled to the embedded circuitry by one or more vias. The one or moreinductors and/or capacitors can overlap at least partially or completelya footprint of the embedded circuitry. For example, an AC-DC convertercan be similar to FIG. 3, wherein component 315 is embedded circuitry(e.g., an IC) 2640.

The power converters disclosed herein, including DC to AC converters, ACto DC converters, AC to AC converters, and the examples in FIG. 26A,FIG. 26B, and FIG. 26C can be chip embedded, in whole or in part, basedon the principles and disclosures provided with reference to DC-DCconverters.

Additional Embodiments

To aid in understating, some embodiments are described with reference toexample values, such as voltage values, sizes, frequencies, currents,positions, etc. However, the disclosure is not intended to be limited tothe values disclosed herein. For example, the voltages ranges associatedwith DC-DC converters can include any voltage range. Various embodimentscan use any range of input voltages and any range of output voltages,including converting between positive and negative voltages, such as a+12V to −5V DC-DC converter. Various embodiments can similarly use anycurrent value, including very high current values exceeding 200 amps.Various embodiments can have arrangements of components that are indifferent positions and/or orientations. For example, any of theintegrated circuits disclosed herein can be face up or face down.Although some examples disclose certain communication systems such asI2C and/or PMBUS, communication systems or other protocols and/orphysical layer designs can be used. Other embodiments can use, forexample, Serial Bus ID (SVID), Adaptive Voltage Scaling Bus (AVSbus),and the like. The controllers disclosed herein can be implemented in avariety of ways, such as with digital implementations, analogimplementations, and hybrid implementations. Some DC-DC converterpackages or PCBs can include a capacitor and/or capacitor thereto. SomeDC-DC converter packages or PCBs can be without a capacitor and/orcapacitor coupled thereto; the inductor and/or capacitor can be lateradded to the package or PCB. Some embodiments can be AC coupled. Thepair 1215 of inductors 1211, 1215 in FIGS. 13A and 13B can be inductorsthat share a single core. Although some example systems were describedwith respect to example feedback control schemes, the power convertersdisclosed herein can use any feedback control scheme. The powerconverters can use current mode control schemes based on averagecurrent, peak mode, valley mode, emulated current, etc.; voltage modecontrol schemes based on leading/rising edge, driving edge, dual edge,etc; constant on time; constant off time; etc. Feedback systems caninclude hysteresis.

The power converters can be used to power various devices, such as IoTdevices discussed with respect to FIG. 22. The CPU 2205 shown in FIG.22, and any other controllers, processors, etc. discussed herein, can bea hardware processor, or multiple hardware processors, which can becoupled with buses for processing information. The CPU, processor,controller, etc. can be, for example, one or more general purposemicroprocessors.

The CPU, processor, controller, etc. can be coupled to main memory, suchas a random access memory (RAM) 2207, cache and/or other dynamic storagedevices, coupled to buses for storing information and instructions to beexecuted by processor 2205. RAM also can be used for storing temporaryvariables or other intermediate information during execution ofinstructions to be executed by the CPU 2205. Such instructions, whenstored in storage media accessible to processor 2205, render a computersystem into a special-purpose machine that is customized to perform theoperations specified in the instructions. Any suitable type ofcomputer-readable memory can be used.

The electrical system 2201, or others disclosed herein, can includedevices 2211 such as a display (e.g., a cathode ray tube (CRT) or LCDdisplay or touch screen) for displaying information to a user. Otherexamples of devices 2211 include input devices, including alphanumericand other keys, for communicating information and command selections toprocessor 2205. Another type of device 2211 is a cursor control device,such as a mouse, a trackball, or cursor direction keys for communicatingdirection information and command selections to processor 2205 and forcontrolling cursor movement on a display. This input device typicallyhas two degrees of freedom in two axes, a first axis (for example, x)and a second axis (for example, y), that allows the device to specifypositions in a plane. In some embodiments, the same directioninformation and command selections as cursor control can be implementedvia receiving touches on a touch screen without a cursor.

The electrical system 2201, or others disclosed herein, can include auser interface module to implement a GUI that can be stored in a massstorage device as executable software codes that are executed by thecomputing device(s). This and other modules can include, by way ofexample, components, such as software components, object-orientedsoftware components, class components and task components, processes,functions, attributes, procedures, subroutines, segments of programcode, drivers, firmware, microcode, circuitry, data, databases, datastructures, tables, arrays, and variables.

In general, the word “module,” as used herein, refers to logic embodiedin hardware or firmware, or to a collection of software instructions,possibly having entry and exit points, written in a programminglanguage, such as, for example, Java, Lua, C or C++. A software modulecan be compiled and linked into an executable program, installed in adynamic link library, or can be written in an interpreted programminglanguage such as, for example, BASIC, Perl, or Python. It will beappreciated that software modules can be callable from other modules orfrom themselves, and/or can be invoked in response to detected events orinterrupts. Software modules configured for execution on computingdevices can be provided on a computer readable medium, such as a compactdisc, digital video disc, flash drive, magnetic disc, or any othertangible medium, or as a digital download (and can be originally storedin a compressed or installable format that requires installation,decompression, or decryption prior to execution). Such software code canbe stored, partially or fully, on a memory device of the executingcomputing device, for execution by the computing device. Softwareinstructions can be embedded in firmware, such as an EPROM. It will befurther appreciated that hardware modules can be comprised of connectedlogic units, such as gates and flip-flops, and/or can be comprised ofprogrammable units, such as programmable gate arrays or processors. Themodules or computing device functionality described herein arepreferably implemented as software modules, but can be represented inhardware or firmware. Generally, the modules described herein refer tological modules that can be combined with other modules or divided intosub-modules despite their physical organization or storage

The electrical system 2201, or other systems described herein, canimplement the techniques described herein using customized hard-wiredlogic, one or more ASICs or FPGAs, firmware and/or program logic whichin combination with the computer system causes or programs (e.g., ofelectrical system 2201) to be a special-purpose machine. According toone embodiment, the techniques herein are performed by electrical system2201 in response to processor(s) 2205 executing one or more sequences ofone or more instructions included in main memory 2207. Such instructionscan be read into main memory 2207 from another storage medium, such asstorage device. Execution of the sequences of instructions included inmain memory 2207 causes processor(s) 2205 to perform the processoperations or implement the features described herein. In alternativeembodiments, hard-wired circuitry can be used in place of or incombination with software instructions.

Non-transitory computer readable media can be used. Any media that storedata and/or instructions that cause a machine to operate in a specificfashion can be used. Such non-transitory media can comprise non-volatilemedia and/or volatile media. Volatile media includes dynamic memory,such as main memory 2207. Common forms of non-transitory media include,for example, a floppy disk, a flexible disk, hard disk, solid statedrive, magnetic tape, or any other magnetic data storage medium, aCD-ROM, any other optical data storage medium, any physical medium withpatterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, NVRAM, anyother memory chip or cartridge, and networked versions of the same.

Non-transitory media can be distinct from but can be used in conjunctionwith transmission media. Transmission media can participate intransferring information between non-transitory media. For example,transmission media can include coaxial cables, copper wire and fiberoptics, including the wires that comprise buses. Transmission media canalso take the form of acoustic or light waves, such as those generatedduring radio-wave and infra-red data communications.

The wireless communication system 2103 can provide a two-way datacommunication coupling to a network 2213. For example, wirelesscommunication system 2103 can send and receive electrical,electromagnetic or optical signals that carry digital data streamsrepresenting various types of information. Alternatively, in some casesa wireless communication system 2103 can provide one-way communication(e.g., receiving or transmitting information).

Network 2213 typically provides data communication through one or morenetworks to other data devices. For example, network 2213 can provide aconnection through local network to a host computer or to data equipmentoperated by an Internet Service Provider. The ISP in turn provides datacommunication services through the world wide packet data communicationnetwork now commonly referred to as the “Internet”.

1. (canceled)
 2. A power converter comprising: a printed circuit board(PCB) that includes an upper side and a lower side; embedded circuitrythat is chip-embedded between the upper side of the PCB and the lowerside of the PCB, the embedded circuitry including one or more switches;a driver configured to generate one or more driver signals for drivingthe one or more switches; and one or more vias extending through theupper side of the PCB; an inductor external to the PCB and positionedover the upper side of the PCB, wherein the one or more viaselectrically couple the inductor to the embedded circuitry, and whereina footprint of the inductor at least partially overlaps a footprint ofthe embedded circuitry; an input coupled to the embedded circuitry, theinput configured to receive an input voltage; and an output coupled tothe inductor, the output configured to provide an output voltage that isdifferent than the input voltage, wherein the output voltage is based,at least in part, on the one or more switches causing the inductor tocharge and discharge.
 3. The power converter of claim 2, wherein theembedded circuitry includes the driver.
 4. The power converter of claim3, wherein the embedded circuitry comprises a pulse width modulator(PWM) controller configured to generate one or more PWM signals, whereinthe PWM controller is coupled to the driver, and wherein the driver isconfigured to generate the one or more driver signals based at least inpart on the PWM signals.
 5. The power converter of claim 2, wherein thedriver toggles the one or more switches at a frequency between 1 MHz and15 MHz.
 6. The power converter of claim 2, wherein the driver togglesthe one or more switches at a frequency between 2 MHz and 15 MHz.
 7. Thepower converter of claim 2, wherein the one or more switches includes afirst enhanced gallium nitride (eGaN) switch and a second eGaN switch.8. The power converter of claim 2, comprising a ramp generatorconfigured to generate a signal that emulates a current ripple throughthe inductor.
 9. The power converter of claim 8, wherein the rampgenerator is configured to generate the signal that emulates the currentripple through the inductor at least in part using: a first inputindicative of the input voltage; a second input indicative of the outputvoltage; a third input indicative of an inductance value of theinductor; and a fourth input of a switching signal.
 10. The powerconverter of claim 8, wherein the one or more switches comprises a firstswitch and a second switch, and wherein the ramp generator comprises: afirst current source configured to generate a current based, at least inpart, on the input voltage; a second current source configured togenerate a current based, at least in part, on the output voltage; athird switch configured to receive at least one of the one or moredriver signals, the third switch coupled to the first current source; afourth switch configured to receive at least one of the one or moredriver signals, the fourth switch coupled to the second current source;and a capacitor coupled to the third switch and to the fourth switch.11. The power converter of claim 2, wherein the power converter isconfigured with an isolated topology configured to isolate a directelectrical connection between the input and the output of the powerconverter.
 12. The power converter of claim 11, wherein the isolationtopology comprises a transformer that includes a first inductor and asecond inductor configured such that a changing current through thefirst inductor induces a changing current in the second inductor. 13.The power converter of claim 2, wherein one of the inductor and theembedded circuitry has a footprint entirely within a footprint of theother of the inductor and the embedded circuitry.
 14. The powerconverter of claim 2, comprising a communication interface configured toreceive a control signal for adjusting an output of the power converter.15. The power converter claim 14, wherein the communication interfaceincludes a Power Management Bus (PMBUS).
 16. The power converter claim14, wherein the communication interface is configured to implement aninter-integrated circuit (I²C) protocol.
 17. The power converter claim14, wherein the communication interface comprises a wirelesscommunication system in a same package as the embedded circuitry. 18.The power converter of claim 2, comprising an AC coupling capacitor. 19.The power converter of claim 18, wherein the one or more switchesinclude: a first switch between the input of the power converter and theAC coupling capacitor; and a second switch between the AC couplingcapacitor and ground.
 20. The power converter of claim 2, wherein thepower converter is a direct current to direct current (DC-DC) powerconverter.
 21. A power supply system comprising a first power converteraccording to the power converter of claim 2, wherein the power supplysystem further comprises: a second power converter coupled in parallelwith the first power converter; and a control system configured toadjust an output of the first power converter and an output of thesecond power converter for current balancing.